Webcomic / Yumi's Cells

Yumi's Cells is a Korean Webtoon by Donggeon Lee.

Yumi Kim is a 32-year-old office worker. Somewhat shy and introverted, she has trouble socializing, but likes cute things and still hopes she can find her One True Love.

This is her story, but also the story of her brain cells.

Represented as little blue-suited men and women such as the Anger Cell, Rational Cell and Emotional Cell; they argue, take counsel together, and occasionally fight each other for control. All in an attempt to keep Yumi functioning day-to-day and prevent her from suffering too many embarrassments.

The official English translation, which began on May 27th, 2015, and ended with 511 chapters on December 15th, 2020, can be read here.

A live-action/animated hybrid series premiered on September 17th, 2021.

See also Inside Out, the Pixar film with a very similar theme, Poison Berry in My Brain for the Japanese equivalent, and Herman's Head for a live-action American sitcom take on the concept.

Daily JoJo, the author's follow-up comic, is set in the same universe.

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Contains examples of:

• Accidental Hand-Hold:
  • On Yumi and Woong's blind date, Yumi goes to pay for the food, but Woong grabs her hand to stop her. This causes her heartbeat energy to go up.
  • Post Love Confession, Yumi invites her latest love interest to her apartment for dinner. She accidentally grabs his hand when he heads in the wrong direction, which equates to her Naughty Cell glomping his Love Cell without warning.
• Acme Products: Julie, the author's wife, seems to be the brand name for everything that isn't a Product Placement, from restaurants to jewelry brands to the university Yumi went to.
• Age-Gap Algebra: To highlight Yumi's insecurity about her age, her cells have a laugh about what a six-year age gap means: While Yumi was in university, Wook was just starting middle school.
• Age-Gap Romance:
  • Yumi goes after Wook, who is six years her junior, and feels insecure about the age gap at times. They seem to make progress at the flower festival, but when he calls her out of the office seemingly to ask her out, he reveals that he's not interested in women and sets her up with Woong, who is her age.
  • Daeyong ends up with Yunhee, who is at least nine years younger and Ruby's junior, safely avoiding the conflict of their feelings for Yumi and Babi respectively.
  • 23-year-old Da-eun is smitten with Babi, who is in his mid-thirties. The crush is mutual and causes some tension in Babi and Yumi's relationship. Da-eun and Babi eventually get together when Yumi breaks up with Babi for good.
• All Men Are Perverts: While Yumi's Naughty Cell is a force to be reckoned with, the men have much more troublesome Naughty Cells.
  • Woong's Naughty Cell has a pet Naughtysaurus whose strength is comparable to Yumi's Hunger Cell.
  • Control-Z lacks a Love Cell, so his Naughty Cell responded first to a love confession with an attempted kiss.
  • Soonrok tends to unintentionally summon his Naughty Cell, which is a Gentle Giant that recharges him even though he didn't ask for it.
• Amicable Exes: Yumi and Woong reach a point at which they can congratulate each other on their life achievements.
• And Another Thing...: Sia intrudes on Yumi and Woong's date, leading them to bring Wook and Ruby along. Since Sia can't get a good read on Yumi with that many people, she decides to leave, dropping a "bomb" in front of Yumi on her way out in the form of hinting that she's moving to the same apartment as Woong.
  Sia: Ah, right! Woong, let's talk about me moving <again> tomorrow.
• April Fools' Day: The episode that ends with a Love Confession was released on April 1 in the original Korean version. This kept the two Daydream Surprises in the following episode from being too easily spotted due to the Foregone Conclusion.
• Art Evolution: The art goes from universally short and stubby for both cells and humans to more proportioned, even adding highlights and eye colors. Chapter 399 lampshades this, as Yumi comments that she looks the same as ever while the cells make a side-by-side comparison to her earlier and newer art to deny that.
• Artifact Title: The story stopped solely being about Yumi's cells as soon as we peeped into another person's brain. In addition, the story is much more about Yumi than her cells anyway, and only increasingly becomes such as the years roll on.
• Attack of the 50-Foot Whatever:
  • When Yumi experiences a particularly strong determination, the relevant Cell swells to Hunger Cell's size or larger and gets to have its way in her town. It can last up to a few days.
  • Isabelle's Conscience Cell grows big and hunts down her Writer Cell to represent her guilt over plagiarizing.
• Badass Cape: Many Prime Cells wear a cape to complement their special powers and distinguish them from the other cells.
• Bait-and-Switch:
  • Yumi pines for her coworker Wook and is overjoyed when he asks her out... until he reveals he's gay and is actually trying to set her up with a friend of his, Woong.
  • Babi has a lot of death flags towards the end of Part 2, from mysterious voices telling him to cherish his girlfriend to a shot of his broken cellphone as he narrates his many failings in life. He even gets to watch his life flash as a ghost disconnected from his body... but that build-up leads to the reveal that the car stopped in time and that he was just standing frozen in the street.
  • Part 2 ends with Yumi and her beau returning to the beach where she thought he'd propose to him, this time with a ring in tow. Later on in part 3, we learn it was just a ring he wanted to give her... which turned out to be one half of a set of matching wedding rings.
• Bait-and-Switch Sentiment: During Yumi's wedding, her mom calls out to her but is too far to be audible. Yumi believes that her mom is wishing for her to be happy, but her mom is actually telling her not to cry or it will ruin her makeup.
• Battle in the Center of the Mind: In Chapter 54, Love Cell and Hysterious fight as Yumi becomes feverish from a combination of things that happened earlier in the day.
• Became Their Own Antithesis: When Yumi gets upset with her cells' indecisiveness during her attempt to break up with Babi, Love Cell, Fashion Cell, and Cheapskate Cell morph into their opposites. Fashion Cell becomes a Fashion Terrorist that forces Yumi to dress frumpily, Cheapskate Cell becomes a Giving Tree that spends willy-nilly, and Love Cell becomes Anger Incarnate and impedes Yumi's ability to date.
• Beta Couple: Every Official Couple that doesn't involve Yumi seem to develop a lot faster and lacks the ups and downs that Yumi's relationships faces.
• The Big Guy:
  • Hunger Cell is the largest Cell in Yumi's village and can brute force decisions that other Cells struggle to make.
  • Soonrok's largest Cell, Naughty Cell, is muscular, proportionate, and at least as large as he is. He's a Gentle Giant, but he tends to show up and help when Soonrok (thinks he) didn't ask.
• Bite of Affection: The Crocodile Counterattack, from the Cutie Bible, is a shoulder bite that is said to energize the person being bitten. Yumi tries to use it on Babi, but it doesn't elicit much of a response from him.
• Blind Date:
  • Wook sets up Woong and Yumi on a blind date because he believes both of them are good people who deserve a date. Yumi's first impression of Woong is lukewarm, but they hit it off.
  • Daeyong sets up introverts Soonrok and Soohyun. It doesn't work because Soonrok is too comfortable around her and Soohyun is expecting the ice part of his Sugar-and-Ice Personality.
• Book Ends: Some chapters start and end with the same sentence. For example, "Couple T-shirts always bring love with them," and "Dating is a heart-throb battle."
• Brain with a Manual Control:
  • In Chapter 20, Naughty Cell hijacks the controls for Yumi's right hand so that her fingers are making contact with Wook's.
  • In Chapter 108, this extends to Naughty Cell tampering with Yumi's hands and center of gravity in an attempt to become closer to Woong, with Manner Cell trying to stop him the whole time.
• Break-Up/Make-Up Scenario: Babi and Yumi initially break up because the former had gained a small crush on his employee Da-eun Yoo, on top of lending her his jacket when they both know she's a Smitten Teenage Girl, and stay separated for at least a few months. They get back together the day they meet up again, but while they try to make the relationship work, Yumi has completely fallen out of love with Babi and couldn't accept his marriage proposal, and they go part ways for good.
• Bridal Carry: When Yumi collapses with a fever, Woong carries her to the hospital like this. He even thinks "Carry my princess!" as he goes.
• Brought Down to Normal: Love Cell is unable to use her skills after being demoted from Prime Cell. She's even wearing the regular blue suit rather than her special pink suit.
• But Not Too Gay: Wook. While he comes out to Yumi very early into the series and has his own love interest, we never see the guy and Wook is usually playing off of Woong (his buddy) or Ruby (his most persistent admirer). The guy shows up in Chapter 504 but isn't named.
• Call-Back:
  • Yumi's first encounter with Babi has him drawn in a deliberately crude and colorless style, showing that she didn't particularly care for him— and when he finally catches her attention, he stops being drawn that way. This scenario happens again when they begin dating a second time, since Yumi's feeling less than enthusiastic about him until he admits what's on his mind and wants to make their relationship really work again.
  • Babi once comments on his girlfriend's eyes, saying in a rhetorical triangle that he likes them most when they're sparkling with interest/love. When he finds Yumi's eyes aren't sparkling around him, he begins to get worried, and thinks in that same rhetorical triangle again.
  • When Woong stays over at Yumi's house, she tries to hide her food by shoving it in an empty space in her book shelf. Years later, she sifts through the shelf and finds those same cookies, but expired.
  • Woong, post-breakup, mentally time travels so he can interrupt his younger self from saying the things that broke his relationship with Yumi and tells her what's really going on in his mind. Later on, Babi does the same thing when he mentally talks to all of the girls in his failed relationships so he can get his record straight.
  • Yumi draws a line with Woong when he drops hints that he wants to get back together with her. When she develops a crush on Assistant Manager Shin and drops hints for him, he draws the line much more pointedly.
• The Cameo: Nani from A Bittersweet Life shows up in Chapter 32 to get Yumi to express her feelings about not getting to date Wook.
• Career Versus Man:
  • Sia masks her romantic feelings for Woong and avoids pursuing him because having a boyfriend would hinder her ambition to be a famous art director.
  • In a gender-inverted version, Soonrok demonstrates that he's fully prepared to lose his entire career if his boss finds out who he's dating.
• Cassandra Truth: Nobody listens to the Sixth Sense cell. Whenever he tries to warn the rest of the cells about something big, they always dismiss him until the last moment, saying his job's already being fulfilled by other cells and modern technology. They at least start paying attention to him later, but for the most part he's isolated from the rest.
• Catapult Nightmare: Yumi sits up in bed after having a dream that Ruby and Wook slept together.
• Chuck Cunningham Syndrome:
  • Woong's Joke cell vanishes from his mind in the later series, with no one making a peep about his whereabouts.
  • Yumi's friends from the earlier episodes disappear after a few time skips. Of those who predate her relationship with Woong, only Ruby and Eda make it to the penultimate episode.
• Cleaning Up Romantic Loose Ends:
  • Eda, after backing down from her crush on Babi, ends up with the glasses-wearing coworker that seemed to be into her.
  • Yumi's chief editor and Lihyun fall for each other at first glance, ridding him of his college crush on Yumi and her of her fascination with Babi.
  • Control-Z, who's been out of a relationship for years, and Ruby, who has a hopeless crush on Wook, also fall for each other pretty quickly. This gets rid of their lingering plots, such as his baggage after his long term girlfriend died and her finally getting over Wook.
  • The Flash Forward three years shows that after Babi and Yumi break it off, he gets together with Da-eun and has a child by her.
  • Woong agrees to have dinner with Jenny, the woman who bought the last copy of a special edition of Yumi's latest novel.
  • While Wook mentions that he's already in love with another man early on in the series, it's not until the end that we actually see his steady. He's made progress with him.
• Clingy Jealous Girl: There are too many to count:
  • Woong's best friend, Sia, has her feelings for Woong arise again when Woong and Yumi start going out. She and her cells have been hiding repressed emotions for Woong because of fear that it would get in the way of her job.
  • Ruby is pretty hostile to anyone who she thinks is eyeing Wook, and even attempts to get in their way. She stops doing this when she gets over him.
  • Yumi has also shown herself to be this at times. She doesn't like any of her boyfriends looking at other women, and is frequently trying to look into matters to see if her love rivals are real threats or if her beau is cheating on her. Both times she seriously got jealous, she was somewhat right; Sia's case is relayed above, while the other incident involved an employee of Babi's that was a little smitten with him.
  • Ironically, Yumi was on the receiving end of this behavior with the wife of her part-time job's manager. Since Yumi is a reasonably attractive girl, the wife drops in regularly to see if Yumi is making a move on her man or vice versa.
• Cock Fight: Woong and Babi get into one in Part 3 when they meet at the hospital, in true The Missus and the Ex fashion. Yumi puts a stop to it by making clear where her priorities are in love.
• Color-Coded for Your Convenience: Since most cells look the same, their uniform colors are often made different to showcase whose head we're in at the moment:
  • Yumi's (with the exception of her Primed Love and later, Writer when he becomes a Prime) wear a sky blue, whereas Woong has a navy blue instead.
  • Ruby's cells are violet.
  • Babi's are dark green. Sia's are also a deep green.
  • Shin's are yellow-orange. His Prime Love Cell is nearly the same shade of blue as Yumi's normal Cells and looks right at home with them.
• Combined Energy Attack: Parodied in Chapter 142 when Yumi's Love Cell gathers the energy from the other Yumis in the world to create their <Oh Please> attack.
• Contrived Coincidence: The day Babi really started having trouble with his ex-girlfriend was the day he found Yumi's umbrella. The ex commenting on it makes him go off to find Yumi the next day, leading to their breakup and his eventual get-together with the latter girl.
• Costume-Test Montage: Chapter 10 has Yumi trying on different outfits, to which Fashion Cell all rejects.
• Creator Cameo: In the "Babi Zone" chapters, Yumi bumps into the author and gets his autograph after momentarily being star-struck.
• Crush Blush: The effect of Naughty Cell setting Yumi's village on fire, which he tends to do when she's around someone she likes.
• Custom Uniform: Aside from the Prime Cells' Earned Stripes, some Cells wear accessories with their jumpsuits to distinguish themselves from generic background Cells. For example, Detective Cell has a cape, Kindness Cell wears a skirt, and Naughty Cell forgoes the pants.
• Daydream Surprise:
  • After Yumi and Woong get into a fight, Yumi decides they'll be broken up if he doesn't text her by the time the Breakup Alarm goes off. Over the course of five years, Woong doesn't contact her even once. Yumi's coworker offers to warp her back in time so she can make things right, and she snaps out of the effects of the Scenario skill.
  • In "Heart Fever Time", Soonrok imagines two scenarios. While the second leans towards an Imagine Spot due to it being a Foregone Conclusion, it's so seamless that the unaware reader could take it for real. The first is when he runs into Yumi at the same bookstore a year later, but she already has a boyfriend. In the second, he turns back without calling Yumi out of her house and receives an invitation to her wedding some years later.
• A Day in the Limelight: The "Ruby, Signing Off" series of comics puts focus on Ruby and Control-Z, who begin to get over their respective love dilemmas and fall for each other.
• Dead Sparks: Following a Break-Up/Make-Up Scenario, Yumi sees her boyfriend as a messy, colorless sketch. She's eventually able to see his face again when they resolve to make their relationship work, but they break up for good after Da-eun drunk-dials Babi and Yumi is completely unbothered.
• Death Glare: The "Yumi Laser Beam". Yumi uses it on the back of Ruby's head so she feels the heat, turns to see Yumi glaring at her, and leaves Wook alone. Much later on, Yumi uses it when Soonrok mentions her ex's name, but it doesn't really affect him other than by making it clear it's a sore subject.
• Déjà Vu:
  • Explored extensively in "The Signals You Get" saga. This turns out to be the work of the Telepathy Cells telling Yumi that she'll have a big break three and a half years in the future.
  • Yumi gets a few with her eventual soulmate. When they first meet, she believes they had met before. At the end of the "Date" episodes, he gets déjà vu when she puts a band-aid where his wedding ring should go. Finally, they have a few glimpses of their wedding on their trip to Jeju Island, which transitions to their actual wedding.
• De-power: In Chapter 51, Hunger Cell loses his will to eat when his appetite antenna is torn out.
• Did They or Didn't They?: After several chapters teasing whether Yumi will stay the night at Woong's place, Chapter 82 reveals that they fell asleep while holding hands while also suggesting a big chunk out of the story was left out.
• Domesticated Dinosaurs: Chapter 78 introduces us to Woong's Naughtysaurus, his Naughty Cell's pet.
• Dream Within a Dream: Chapter 95 has Yumi waking up at work and talking about her wonderful dream of a romance with Woong (who is a movie star in a relationship with Sia), then waking up from that dream. Cue "OMG AUTHOR YOU JUST GAVE ME A HEART ATTACK" comments from the readers.
• Earned Stripes: A Prime Cell (the person's most important cell who will usually be seen as the leader) will often be marked by a change in wardrobe and slightly in color to differentiate them from the regular cells. Yumi's Love cell turned pink and got a cape, while when Writer cell got promoted, he obtained a green Shakespearian outfit.
• Eating the Eye Candy: When Soonrok climbs a flight of stairs in front of Yumi, she's clearly looking at his butt and blushing.
• Emotion Suppression: In general there's a prison made for emotions that are the least help to the main body, so all of those emotions never have a chance to express themselves. However, there is always one cell, in particular, that does more damage than most, who gets locked deep within the mind and only brought back in landmark situations. In Yumi's case, it's her Inner Feelings Cell; in comparison Babi's Overreaction Cell and Sia's Emotional Cell are their main problems.
• Entitled to Have You: Subverted with her ex Wook. Confidence being his prime cell, he swaggers back into her life, assuming she will fall back into his arms. When she stands up to him and gives a firm "no", he seems to get a grip on himself and backs off.
• Evil Versus Evil: When Ruby and Sia meet and have dinner with Wook, Yumi, and Woong, Sia mistakenly thinks Ruby is after Woong, while Ruby thinks Sia is angling for Wook. They end up in an escalating Passive-Aggressive Kombat fight of trading backhanded complements and snide remarks.
• Eye Beams: Parodied when the "Yumi Laser Beam" is used in Chapter 28 by Yumi to inflict a Death Glare onto Ruby.
• Finger Muzzle: Yumi's boyfriend shushes her when she tries to ask why he's being cold when they're in the office because their relationship is supposed to be a secret.
• The First Cut Is the Deepest:
  • At the start, Love Cell has been in a coma for three years because Yumi's last boyfriend was with her for most of her twenties before he suddenly dumped her.
  • Control-Z has closed himself off from the dating scene because of his girlfriend of ten years, who died in a car accident.
• Fisher King: The inside of the brain for all sapient beings. When the person's happy, it loses gravity and goes pink; when they're sad, it rains and can even flood, etc.
• Flash Forward: "The Signals You Get" shows us flashes one and a half years into the future, and three years into the future via Telepathy cells. In both flashes, we see Yumi becomes a successful writer and a married woman, Control-Z and Ruby are still together, Wook's still got his company, and Babi and Da-eun hook up and get married a year and eight months from the present.
• Food as Bribe: In Chapter 32, Nani gets Yumi to open up about what's been bothering the latter by offering her fried chicken; in the inside world, Hunger Cell breaks open the Vault of Secrets in promise of the food.
• Foreshadowing:
  • Yumi's writing hits a slump at one point in her relationship with Babi because he was her ideal man, to which no love interest she wrote could compare. She also got criticism from her artist, Control-Z, for writing relationships he sees as unrealistic. Her writing actually takes a turn for the better when she and Babi break up, since she now knows about more realistic situations.
  • Yumi's jealousy flares up when she sees Da-eun working at Babi's Tteok bokki restaurant. She's right to do so—aside from the New Year's incident, Da-eun proved to be a legitimate love rival due to Babi's fleeting crush on her, eventually leading into them coupling months after she quits working for him.
• Fourth-Date Marriage: Downplayed; a time-skip gives Yumi less than a year and four months to start dating again and get married. For comparison, that's how long she dated Woong before they broke up.
• Fusion Dance: Cells can fuse to become more powerful. Ruby's Love and Liar Cells become Foxy Cell, Woong's Geek Prime Cell is a combination of his Love and Hobby Cells before Yumi splits them apart, and Yumi's Confidence and Inner Feeling Cells become Checkmate Cell for a short time.
• The Ghost: Math Cell is dead from the start and its tombstone is depicted whenever Yumi needs it to demonstrate that she's bad at math. It's still acknowledged as dead in the second-to-last chapter.
• Ghost in the Machine: Inside the body live the Cells that control all a person's actions. Each Cell has a specialized function or manner of thinking, and a person's Prime Cell tells a lot about their personality.
• Growling Gut: Yumi's stomach will growl if Hunger Cell plays the Belly Flute.
• Harsh Word Impact: The Beast from Hell "Kitty", a being that leaves stinging scratches on other people's pride when the main person says something insulting to another in the outside world.
• Heroic Resolve:
  • When Woong needs to carry Yumi several blocks to the hospital, his brain cells summon this.
    NOW, RELEASE EVERY CARB IN HIS BODY!! WE'RE GOING INTO RUNNING MODE!!!
  • Soonrok goes into the state of Heart Time Fever when he realizes his feelings for Yumi, leading him to bike all the way to her house at night and confess his feelings to her.
• Hesitation Equals Dishonesty: When Yumi asks Babi if he was swayed by Da-eun, his Overreacting Cell wants to be honest while his Love Cell wants to tell Yumi what she wants to hear. Their argument causes them to miss the time limit of the question, and Babi's hesitation tells Yumi all she needs to know.
• Hint Dropping: Yumi tries to drop hints when she has a crush on Assistant Manager Shin, like inviting him to see a movie. When he catches on, he draws a line, leading her to take back the hints.
• Hopeless Suitor:
  • Neither Yumi nor Ruby has a chance with Wook because he has an Incompatible Orientation with them. He's interested in someone else.
  • Daeyong tries to court Yumi after becoming her publisher, but he's unaware that she's already in a relationship with Babi. He backs off once he finds out and ends up with another woman.
• Hysterical Woman: One of Yumi's recurring cells is Hysterius, a mischievous boy who wants to make Yumi release all of her pent-up frustration. Hysterius cells also exist in other people, but it's only consistently been Yumi with one to stir up trouble.
• Identical Panel Gag: The Cells' uniform shape makes it easy to swap them out for each other, allowing for multiple Cells to face the same situation in the same scene in quick succession. For example, Rational Cell tosses Emotional Cell into a freezing lake to wake her up, and she quickly returns the favor.
• In Another Man's Shoes: Yumi sometimes is put into this position. Her getting side-eyes from her bookstore manager's wife gets replicated when she learns Babi's employee has a crush on him, and she gets a little bit of perspective on Woong's coming between her and Sia when she does the same thing to Woong and Babi.
• Incompatible Orientation: Yumi's crush on Wook ends when he sets her up on a blind date and reveals that the person he's interested in isn't a girl. Ruby has no chance with Wook either.
• Inconsistent Dub: The Cells have had different names over the course of the series. Alternate names include Etiquette Cell for Manner Cell, Jump-the-Gun Cell for Jinx Cell, and Hungry Cell for Hunger Cell, the latter of which became a permanent change. One-Step-Behind Cell was also referred to with female pronouns early on but male pronouns a few hundred episodes in.
• Indulgent Fantasy Segue: When Control-Z makes fun of Yumi for ordering ginger pie, she lunges at him and throws him to the ground before chuckling at this imagined scenario.
• Informed Ability: Yumi's writing. While we do learn that she loses a few contests and eventually writes a popular web novel, we don't get many actual looks into her writing style and can only glean from what the others tell the audience.
• In My Language, That Sounds Like...: Babi means "pig" in Indonesian, so his name caused Indonesian readers quite a bit of amusement. Incidentally, Babi's name couldn't be typed uncensored in the comments for some time after Yumi and Babi broke up for good.
• Ironic Echo: Sia's confrontation with Yumi ends with Woong getting in between the two of them when they take it too far, specifically holding off Yumi. In Part 3, Kwoong's on the receiving end of this, as Yumi breaks up his spat with Babi to make clear to Kwoong that he shouldn't be so quick to judge the latter man.
• I Warned You: One-Step-Behind cells often come at the tail end of a sticky situation, presenting solutions that none of the other cells took and admonishing them for doing the wrong thing. However, they're usually not actually present for said situation, and do this spiel after the worst has passed.
• Kissing Discretion Shot: A few times, when a party is kissing the comic cuts away to represent it as the Tongue cells of the two participants going to each others' houses.
• Last Guy Wins: Yumi has broken up with all her exes with no chance of getting back together a few years before she meets her final boyfriend, whom she marries.
• The Last Straw: When Yumi started dating Woong, Love Cell set up a gourd that represented Yumi's love for Woong. It would not break no matter how much the Cells threw at it. Not even Hysterius's gattling gun of bean bags or Hunger Cell's large bean bag would break it. However, when Manner Cell got upset at the way Woong texted Yumi, a light bean bag that ricocheted off of the pole caused the gourd to break open.
• Limited Wardrobe: Eda always wears the same green dress. She does change her outfit when she gets the spotlight, but she's back to her usual dress afterwards.
• Literal Metaphor: Bombs. Whenever a stressful or frustrating situation has occurred, or someone stews over events, the mind starts creating bombs that can be used to "go off" in the real world. Hysterius used to love making them until he got his hands on a malice spreading gun.
• Loners Are Freaks: Yumi's still single partly because she avoids social activities such as going out drinking with her coworkers.
• Love at First Sight:
  • Daeyong and Yunhee fall for each other at first sight, getting them out of Yumi and Babi's way before it can become a real issue.
  • Da-eun is a self-proclaimed hopeless romantic who falls for Babi right away. Despite her attempts to quell her feelings, she indirectly confesses to him, and they eventually get together after Babi breaks up with Yumi.
• Love Cannot Overcome: Woong ends up breaking up with Yumi after a year and four months, due to his old job going under and his insecurities about not being able to provide for her mixed with his silence about his situation and their general growing incompatibility fueling most of the fire.
• Love Confession: Soonrok confesses his feelings after biking to Yumi's home to deliver a book and an umbrella.
• Love Dodecahedron: Every major character is at the apex of some love triangle. Yumi has had a rival for all of her love interests: Ruby for Wook, Sia for Woong, Eda, Da-eun, and Yunhee for Babi. Furthermore, almost all of her rivals and former love interests find their own love: Wook and Sia have unnamed boyfriends, Eda has an unnamed husband, Yunhee ends up with Daeyong, Ruby gets with Control-Z, Woong dates Angela and then Jenny, and Da-eun and Babi get married.
• Love Epiphany: After the aptly titled "Date" episodes, Soonrok discovers his feelings when he imagines losing his chance.
• Love Makes You Dumb: Rational Cell knows that dating Babi is a bad idea especially when Eda has a crush on him. Unfortunately, the Babi Fan Club beats Rational Cell unconscious as Yumi acts on her feelings. Similarly, Rational Cell winds up in a different dimension as Yumi gets back with Babi after a breakup.
• Love Will Lead You Back: Woong spends some time trying to win Yumi back during the rocky part of her and Babi's relationship, but she puts a stop to it after he winds up in the hospital after his last engineered meet-up.
• Luckily, My Shield Will Protect Me: Chapter 29 introduces the Legendary Shield "Mental Preparation" to predict shocking incidents in advance and absorb 80% of the shock from them.
• Luminescent Blush: Naughty Cell has a permanent blush to indicate his constant lust. He can carry it over to Yumi by setting the town on fire.
• Manchild:
  • The Hunger Cell is a giant building-sized child that is constantly snacking. The others try to keep him under control so Yumi doesn't overeat, but he can get very cranky.
  • Yumi's cells brand Woong as one, describing him specifically as a "sloppy, self-centered person with a boyish heart".
• Married to the Job: Sia, as a means of trying to suppress her love for Wook. Her Love Cell, as a result, isn't focused on romantic love at all; it's actually a love of her career, while her Emotional Cell is the more romantic one.
• Maybe Ever After: Woong gets one with Jenny, a woman who bought the last copy of one edition of Yumi's novel. They are last seen agreeing to go out for dinner.
• Meet the In-Laws: Part 2 features Yumi's parents coming to her apartment to visit her and Babi, while the opposite happens and she meets his father (the mother is dead, though). Both sets of parents approve, but it's subverted since she and Babi don't end up together.
• Moe Anthropomorphism: The cells, representing not only mental functions but also bodily functions. Most of them are cutesy, pudgy little guys in uniforms that run around the brain. Only one person's brain is shown with non-cute cells, and they were freakishly muscular.
• Most Writers Are Writers: In the second Part of the series, Yumi quits her office job to pursue a writing career. She signs on with a publisher, but we don't get to see many other writers other than her.
• Mr. Imagination: Soonrok loves coming up with imaginary scenarios in his alone time and can fully immerse himself in the settings. Yumi takes a page from his book and confronts a rival author in her imagination to come to terms with a plagiarization incident.
• Never My Fault: Yumi's Judge Cell embodies this part of her personality, constantly insisting that other people are at fault whenever she suffers from relationship problems.
• Non-Standard Character Design: Daeyong's cells are realistically proportioned and freakishly muscular. Soonrok has standard Cells, but his Naughty Cell and Tongue Cell take after Daeyong.
• Not a Date: The "Date" saga isn't exactly a date. It starts when Yumi's crush gives back her umbrella and keeps going as they decide to do more activities together. Yumi can't imagine that the man actually reciprocates her feelings, but he goes to her house after the outing and confesses his feelings.
• Oblivious to Love:
  • Yumi is the subject of at last three unnoticed crushes— with a boy she knew in college (who grows up to be her chief editor), with her boss at the office, and with Babi.
  • Woong didn't know how Sia felt about him for the longest time, since she constantly hid her feelings around him and when she actually flirted he didn't know what she was going for.
  • When Babi was in high school, he lent his scarf to a senior, causing her to fall for him. When she called on him to personally say goodbye before graduating, he was oblivious until she told her not to send such a confusing signal. Later on, Babi is completely unaware of Eda's crush on him.
• Office Romance:
  • Yumi starts dating Babi after she moves to his division.
  • Soonrok has a strict rule against this, but he falls for Yumi and starts dating her.
• Official Couple Ordeal Syndrome:
  • Yumi and Woong have to deal with Sia acting like Woong's girlfriend to drive them apart. After Sia steps away from the plot, Woong starts acting distant as a result of his unstable career. Yumi eventually gets fed up with Woong's behavior and wants to break up, but he breaks up with her first.
  • It takes a while for Yumi and Babi to get together because Yumi is still recovering from her last breakup, and she doesn't want to upset Eda, who has an unrequited crush on Babi. After dealing with their exes, a long-distance relationship, and some career changes, Babi hires a part-timer for his tteokbokki restaurant. The girl catches feelings for him and quits, but Yumi breaks up with Babi anyway. They get back together after a few months, but Yumi has fallen out of love with him, and they break up for good.
• Offscreen Romance:
  • Wook reveals to Yumi early on that he's interested in a guy, and that's the last mention of him until Chapter 504 reveals that they got together.
  • Woong hooks up with a Gamer Girl who also helps advertise their games, but we never see how they end up together nor how they eventually break up.
• Opening the Flood Gates: In Chapter 325, when a Cell opens up the full "Tear Duct of Touching Moments", he's promptly washed away by the outpour.
• Painting the Medium: Certain characters will always have their thoughts portrayed as a certain choice menu. Woong often organizes his thoughts into a branching Yes/No chart; Control-Z makes Visual Novel style choices; and Babi's is more normal, but he often numbers his thoughts.
• Pass the Popcorn:
  • In Chapter 18, when Emotional Cell and Naughty Cell get into a Wimp Fight, a bunch of other Cells start spectating and a vendor gives them cell chips to eat.
  • In Chapter 415, Yumi stops dead in her tracks when Babi asks her to give him a minute to speak because her feet Cells are watching the real-life scene play out while eating popcorn.
• Passive Aggressive Combat: A favorite in this series. There are lots of times where a person's seemingly nice comment doesn't reflect their thoughts, and many a fight was to be had about it.
• Pen Name:
  • The author's own pen name, Moving Geon, shows up when Yumi bumps into him and when his book makes #2 on the charts.
  • Soohyun's pen name is Isabelle. When Yumi wants to confront her, she doesn't know what Isabelle looks like despite having met Soohyun.
• Plagiarism in Fiction: After Isabelle reads Yumi's manuscript, she takes one of the ideas for her own story and publishes it first. Yumi is devastated at first but is eventually able to completely let it go, though she still wants Isabelle to face the consequences. Meanwhile, Isabelle is wracked with guilt over her actions.
• Posthumous Character: Math Cell, Travel Cell, and Writer Cell start off dead from disuse.
• The Power of Love: Yumi's Love Cell has a special pink costume and is the most powerful of all. Unfortunately, she was De Powered and put into a coma after Yumi suffered a break-up a few years before the story begins. She starts recovering as Yumi finds a potential new romance.
• Product Placement:
  • Babi gives Yumi a Pandora bracelet full of charms as a gift.
  • Soonrok's favorite snack is Oreos with raspberry cream.
• Punny Name: Most of the characters have one of some sort. Woong's name is a casual way of saying yes, which is used to deliver a Blunt "Yes" to Sia. Daeyong uses his name to give himself the go-ahead, or the opposite if he adds his family name Ahn.
• Rage Breaking Point: Chapter 50, "Yumi Flips Out", in which Hysterious burns down the town with a plethora of stress bombs he made.
• Rejected Marriage Proposal: After Yumi and Babi rekindle their relationship, Yumi brings up the ring he gave her, leading him to propose. She has already fallen out of love, so she turns him down and they part ways for good.
• Rejection Affection: Ruby continues to pursue Wook for three years even though he's clearly not interested in her.
• Retraux Flashback: "The Signals You Get" has Yumi's Telepathy cell send warnings and positive messages to her past selves, with each successive moment drawn in the older art styles.
• Returning the Wedding Ring: Yumi returns her ring after rejecting a marriage proposal and breaking up.
• Sealed Evil in a Can:
  • Inner Feeling Cell is almost always kept locked up lest he end up wreaking havoc by blurting Yumi's true feelings out loud.
  • Babi's Overreacting Cell is similarly locked up because it can wreck relationships by making seemingly kind gestures in inappropriate situations.
• Second Love: Yumi went through a break-up and became emotionally withdrawn. She'd like to find romance again and after a false positive with Wook, she does find it in Woong. Later in the story after the two's breakup, this trope applies to Babi from Part 2 to Part 3, before settling on Shin.
• Secret Relationship: Soonrok and Yumi must hide their relationship because his boss would reassign them if he finds out. When that inevitably happens, they manage to avoid being reassigned by directly bringing the topic up.
• Sexy Discretion Shot:
  • Once Yumi decides to stay the night at Woong's place, it cuts to the morning after. The narrator claims they fell asleep holding hands, but someone asks if the narrator is leaving a chunk out of the story.
  • Chapter 109 starts with Woong giving Yumi a surprise kiss, continues with both parties' Cells using handsy skills, and ends with a shot of fireworks going off outside the window.
  • Chapter 131 ends with Woong canceling his plans with his friend after Yumi yanked his shirt off, claiming that he shouldn't wear that shirt while playing basketball. "Couple T-shirts always bring love with them."
  • Yumi's sleepover with Babi starts with Yumi's Naughty cell wreaking havoc in her mind and ends with the two naked in bed the next morning.
  • After a chapter of relentlessly teasing an audience surrogate who turns out to be Naughty Cell and almost two chapters of a kiss scene that ends with Yumi resting her hand on her boyfriend's butt, the third chapter ends with Yumi and Soonrok resting on the bed wearing different clothes.
• Shirtless Scene: Woong takes his shirt off after he accidentally turns on the shower head and gets soaked. Babi has one leading up to a Sexy Discretion Shot. Soonrok is shown a few times working out shirtless.
• Shock and Awe: Parodied in Chapter 152 when Yumi's Cells utilize her "Lightning Attack"... which turns out to be just Static Electricity.
• Shout-Out:
  • When Yumi's brain cells are arguing over whether to buy Woong a gift of expensive shaving cream, Love Cell flies in and calls for a vote. She asks who the dissenters are while holding a pencil and a Death Note... and suddenly there are no dissenters.
  • In Chapter 74, Love Cell begins to ask Cooking Cell if he wants to build a snowman before interrupting herself.
  • In the English version, Jinx Cell sings "Ca-caw Jinx Style" in the same meter as Gangnam Style in hopes of ruining Yumi's trip to Jeju Island.
• "Shut Up" Kiss: A carefully calculated risk that Soonrok takes when he's trying to find the right moment to kiss Yumi but she's taking too long with her story.
• Significant Name Overlap: Yumi's coworker Wook turns out to have the same name as her ex-boyfriend, and it's likely the reason she fixates on him at first—even internally regarding him as her "destiny" until she decides to give Woong a chance.
• Sir Swears-a-Lot:
  • Naughty Cell has the most censored lines of the cast because he always speaks his dirty mind.
  • Ironically, Kindness Cell swears enough for others to wonder if she was a Swearing Cell all along.
  • Once the Swearing Cell is released from prison, she lives up to her name and cusses out Love Cell for being there.
• Speak of the Devil: When Yumi decides to treat Soonrok to tteokbokki, the latter suggests going to Babi's restaurant to the former's dismay. Fortunately for Yumi, the restaurant is closed, but Babi shows up at the restaurant they end up going to anyway.
• Spear Counterpart: 2017 saw to a male-centric parody of the concept called Genie's Cells (a Spinoff based on the Korean AI TV GiGA Genie), which features the love dilemmas and Cellular activity of a boy.
• Staircase Tumble: Yumi loses her balance while going down a flight of stairs, but Soonrok catches her. Unfortunately, he grabs her by the belly, where she's conscious of the Fat that lives there. She reflexively pushes him away and they both fall the rest of the way down.
• Static Electricity: Chapter 152 has Yumi utilizing this as her "Yumi Lightning Attack".
• Storyboarding the Apocalypse:
  • After Yumi and Woong fight, Yumi decides that they'll be broken up if he doesn't respond by the break-up alarm. Then she imagines what happens five years in the future and decides to make up with him.
  • Soonrok imagines several scenarios of losing his chance to get with the woman he likes because he didn't confess his feelings to her. This keeps him going every time he thinks about turning back.
• Strictly Professional Relationship: Yumi develops a crush on Assistant Manager Shin, but he draws a line when he picks up on her hints. Yumi proceeds to clumsily take back her hints and look for flaws to get over her crush. Once she gets over him, she treats him kindly without any flirty undertones, leading him to let his guard down and eventually fall for her.
• Sugar-and-Ice Personality:
  • Invoked by Daeyong, who initially comes across as aloof and stern, but is secretly very sweet and affectionate. This is because his previous girlfriend broke up with him when he snaps at her once after showering her with too much "sweetness", so now he deliberately saves his warmer side for big moments to make a better impression on his next potential love interests.
  • Soonrok is introverted and operates on "low power mode" at work to save his energy. He only uses his Rational Cell to get through the day, which makes him come across as quiet and emotionless. In his comfort zone, he is a lot more empathetic and affectionate.
• Super Mode: Parodied in Chapter 121 when Yumi's self-esteem levels go up over 3,000 that she enters "Ultra-Yumi Mode".
• Take That, Audience!: In one fourth wall gag, Lee and his wife are shown in bed with Lee criticizing if all women act like Yumi does when it comes to jealousy. His wife and her cells' reaction shows that yes, apparently they do.
• Take Off Your Clothes: When Woong visits Yumi's home, he accidentally turns on the shower and gets his shirt wet. Yumi wants to get him a change of clothes, but her Naughty Cell gets her to blurt out the trope name. Woong obliges.
• Tears of Joy: In Chapter 325, Yumi's tear ducts become full when touched by Babi's words. Unfortunately for her, she ends up looking like she was crying over losing the contest.
• Tempting Fate: Usually the result of Jinx Cell's antics.
• Tertiary Sexual Characteristics: The Cells wear uniform jumpsuits that make their genders hard to recognize, so their hair and accessories provide gender clues. Female Cells tend to have long hair or Girlish Pigtails, and a few of them wear skirts instead of jumpsuits.
• Third-Option Love Interest: Woong proved to be too immature for Yumi. Babi, while more put-together, didn't end up working out. Her third love interest, her Assistant Manager Soonrok Shin, is a balance between the two.
• This Loser Is You: In Chapter 490, a girl is reading the chapter and constantly egging on Yumi to get intimate with her boyfriend. It turns out the girl—and the audience by extension—is Naughty Cell, who promptly gets called out for filling Yumi's head with dirty thoughts.
• Thought They Knew Already: Emotional Cell asks if Hysterious waited until Love Cell was gone before appearing. He didn't know Love Cell disappeared, but now that he does, he sees the perfect opportunity to sabotage Yumi and Woong.
• Title Drop Chapter: The chapters about Yumi's wedding are titled "Yumi's Cells".
• True Love is Exceptional: Control-Z initially dislikes Ruby's overly flirty nature, while Ruby thinks he doesn't hold a candle to Wook. They each entertain the notion that the other one is head-over-heels for them despite not being their type, but they end up falling for each other.
• Trust Me, I'm an X: In Episode 422, when Yumi asks Woong if he even knows how to ride the scooter, he says he majored in engineering. When it's apparent that he's never ridden a scooter before, he says he was a mechanic in the army. Finally, when he rides straight into a wall, he claims he did judo.
• Tuckerization:
  • The author's wife, Julie, seems to own everything from a jewelry brand to a university, as long as it's not a Product Placement.
  • In one Storyboarding the Apocalypse scenario, Yumi gets married to Taehyun Lee, the author's brother.
• Umbrella of Togetherness: When Soonrok is sick and waiting for the rain to pass, Yumi invites him under her umbrella. He is much more sensitive under these circumstances and lets his guard down around her, believing he mistook her for being flirtatious earlier.
• Uncomfortable Elevator Moment: Yumi tries to avoid one with Assistant Manager Shin by waiting in her office until he leaves. They end up getting on the elevator at the same time anyway, and Yumi's attempts to break the silence are met either quickly or silently. They also end up going on the same bus, where she finally breaks through by noticing how he is looking forward to going home.
• Unsound Effect: Kwoong's revelations are often accompanied by the sound effect "Ku-Woong!" whenever he notices something important to him.
• Weight Woe: Yumi is conscious about the Fat that lives in her sides, but her Diet Cell has a soft spot for Hunger Cell and doesn't do anything about her food intake.
• Weird Currency: Yumi's Cells use "Yumi Points" to purchase items.
• Wimp Fight: When Naughty Cell tries to offer some ideas for what to do when Wook arrives, Emotional Cell immediately shuts him down. They get into a slap fight from there.
• Wolf in Sheep's Clothing: The Cell that was once thought to be Babi's Kind-Hearted Cell has wolf ears and is clad in fleece. It turns out to be an Overreacting Cell whose unnecessary kindness to girls he isn't dating tends to get him into relationship troubles.
• World of Technicolor Hair: Yumi herself is blonde, which is very rare for a native Korean unless the person is of mixed ethnicity (which Yumi isn't), and there're others like Da-eun, who has green hair. Yumi being blonde is commented on a few times, but never considered unnatural.
• invokedWrite Who You Know: Yumi's debut work, My Love, Muse, is based off of several people in her life. The heroine is based off of Wook, while the male lead is based off of her own experiences mixed with a boy she knew in college.
• You Must Be Cold: Da-eun leaves Babi's restaurant lightly dressed on a cold day, so Babi lends her a spare jacket. Yumi is concerned that Da-eun might take it the wrong way since it's supposed to be a romantic gesture.

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