A naive high school student determined to enter the university that his brother was unable to after the death of their parents. This leads to him being tutored by his brother's friend, Akihiko, which ends up shaking up his life considerably.
- All-Loving Hero: He cares for others more than himself and forgives everyone easily. Justified that he become this since he thought that he was responsible for his parents' deaths due to his "selfishness", so he will always try his best to refrain himself from being selfish.
- Broken Messiah: His default mode is acting like a Tsundere to Akihiko, along with his usual brash, childish and idiotic personality. Not to mention, anything concerning about Akihiko also can result him into becoming this, too.
- Apologises a Lot
- Attention Whore: Sometimes towards Usagi, since he quickly becomes depressed when he seemingly stopped paying attention to him.
- Berserk Button: Even though he will not admit it, but don't ever try to steal Akihiko from him and don't even talk badly about the latter in front of him. And he is one for Akihiko, for the very same reasons as well.
- Book Dumb: Which was the reason why he had to stay with Usagi in the first place. He got better.
- Butt-Monkey: Almost every ridiculous situation have him as the victim.
- The Cameo: In Sekai-ichi Hatsukoi, he's seen sleeping on the train next to Ritsu.
- Cannot Spit It Out: He doesn't want to say "I love you" to Akihiko, to the point that when he tried saying it out loud, he burst into tears instead. The second time he tried, it came out as barely a whisper.
- The Chew Toy: The Romantica chapters always end with him being in a ridiculous situation.
- Dark and Troubled Past: The death of his parents.
- Don't You Dare Pity Me!: He hates it if anyone becomes obligated to his feelings, but this is because he does not want to burden anyone with his problems.
- Distressed Dude: In the second season where Misaki was curious of Akihiko's past so he willingly went with Haruhiko but then ends up being kidnapped, in a way. He barely managed to subvert this trope by escaping through the window at the cost of spraining his leg, seconds later being held in Akihiko's arms.
- Dude Looks Like a Lady: Some viewers mistook him as a girl sometimes. It gets taken Up to Eleven when you note his other feminine traits such as his housewife-like role, his first name being a unisex name, and his family thinking that he would be born as a girl. At least he uses "ore" though.
- Dude Magnet: At some points, he wonders whether he is producing some kind of pheromone that attracts guys. He even believes that he possesses a pheromone named "Usamone", as he easily attracts and befriends the members of the Usami clan.
- Extreme Doormat: The reason why he keeps getting bullied around, plus he never stands up for himself.
- Genre Savvy: See his page quote. He even breaks the fourth wall at one point; as he was unwittingly jealous with Mizuki who were apparently flirting around Akihiko and bullies him, he regrets that he has wasted so many times on thinking whether Mizuki had a thing on Akihiko when he learns that it's Kaoruko who Mizuki has a thing for.Misaki: (thinking) But what I find even more unsettling... is that I've just wasted four pages straight worrying about this drabble!!! Makes me sick, I tell you!
- Good Is Dumb: He is kind-natured to boot but failed in the academic part in the beginning of the story. Arguably subverted with many of the romantic antics later in the story since he does know and try to not give Ijuuin any HopeSpots regarding romantic relationship.
- The Heart: He is very obsessive about being attentive and caring for people around him, and he doesn't want to be a burden to anyone.
- He Is Not My Lover: Only in the beginning. As the time passes he had slowly accepted the fact that Akihiko is his lover even though he never admitted it out loud.
- Heroic Self-Deprecation: He always mentioned on how he amounts to nothing compared to anyone else. The word "burden" itself is a taboo for him.
- Horrible Judge of Character: Comes with being an All-Loving Hero.
- House Wife: Not literally but he's self-effacing, caring and friendly to everyone, good at housekeeping, etc. He'd be a perfect example of the trope if it weren't for his Tsundere streak when dealing with Akihiko.
- Hyper-Awareness: Even though he barely knew Akihiko in the beginning, he was able to understand the latter's true feelings and cried due to sympathizing with him after Takahiro introduced his bride to Akihiko. Takahiro even points out that he is very attentive towards others around him.
- Idiot Hero: At the start of the story Misaki has rather bad grade on tests, which forced him to study with Akihiko in the first place. He improves eventually.
- It's All About Me: An unintentional example; whether he likes it or not, all of the problems that he needs to deal with the Usami clan are completely centered around him.
- It's All My Fault: He still blames himself for the death of his parents, to the point that he will never tell anyone about his parents' deaths anymore since he will always get the same answer - "It's not your fault." Heck, he has a habit of blaming himself over everything, especially if something goes wrong.
- Jerk with a Heart of Gold: Even though he is brash and abrasive (most notably towards Akihiko), he is actually the most kind-hearted character Nakamura had created.
- Love Epiphany: For a long time, he doubts whether or not he is in love with Akihiko, and finally admitted it in Volume 8. He already had his Love Epiphany some time before that, though. He was just too stubborn to admit it.
- Luminescent Blush: In all of his shy and embarrassing moments.
- Nice Guy
- Oblivious to Love: He's very naive when it comes to love, which makes him prone to be in denial about his feelings for Akihiko.
- Older Than They Look: He doesn't look like an adult at all and still looks like a teenage boy, despite the fact that he is currently 22 years old.
- Only Sane Man: He declared at some times that he keeps meeting weird people everywhere he goes. At some times, he manages to invert this trope by being the center of attention and surprise of everyone.
- Ordinary University Student
- Parental Abandonment: His parents died in an accident when he was eight and his brother Takahiro single-handedly raised him ever since.
- Rape and Switch: Subverted. Misaki does not have any interest in Usagi before and after the latter "jerks him off". He only starts to bond with him after understanding the latter's unrequited love over his brother greatly torments him.
- Real Men Wear Pink: He cooks, does the housekeeping, and can do many thing effectively while staying manly in his own way.
- Second Love: He's this to Akihiko.
- Sibling Yin-Yang: In the beginning, Akihiko always compared Misaki with Takahiro, much to Misaki's dismay. In fact, this is why Misaki initially worried that Akihiko only saw him as a replacement of Takahiro.
- Supreme Chef: H's excellent at cooking and doing housework.
- Sweet Tooth: He loves taiyakis and strawberries, which brought him troubles when Haruhiko or Kaoruko gives them as souvenirs to him.
- Teens Are Short: He is only 162 cm at the start of the story. The anime implies that he is a late grower and he does look taller in the third season.
- Tsundere: A Type B example; he's probably the most kind-hearted example of this trope.
- Uke: Though he does somewhat jokingly say that he wants to top Usagi someday when he grows taller. Usagi accepts the challenge.
Usami "Usagi" Akihiko
Famous author and member of an extremely wealthy and dysfunctional family, he harboured feelings for his friend Takahiro Takahashi for a long time, and took on tutoring his younger brother Misaki as a favour. He ends up falling for him instead.
- Attention Whore: Only towards Misaki. It goes to the point that he gets jealous of Misaki's nephew because Misaki spends his time babysitting rather than hanging out with him.
- Berserk Button:
- He can't keep a cool head when it comes to Misaki.
- He also can't keep a cool head when somebody wakes him up from sleeping, either.
- On a smaller note, don't peek into his notebooks. Though this only applied when he was younger.
- Bridal Carry: He carried Misaki like this the most often compared to the other pairings that Nakamura had created, as this happens twice so far in the manga and sometimes in the covers and the official images.
- The Cameo: In Sekai-ichi Hatsukoi as the author that Ritsu worked for at the beginning.
- Child Hater: As he stated, "[he's] not comfortable around creatures ruled by instinct".
- Child Prodigy: He knew difficult Japanese phrases that Hiroki had to look up despite growing up in England.
- Crazy Jealous Guy: Probably the king of this trope. However, Nowaki does beat him on some occasions.
- Cloudcuckoolander: He buys every type of marimo in the trip to Hokkaido. Also the strawberry and cherry incidents show that he is not altogether of this world.
- Cock Fight:
- Narrowly averted. When he learned about his half-brother's intentions of taking Misaki for himself, hadn't Misaki held him back, he clearly had the intention to go and reality-check Haruhiko with a good punch in the face.
- While they usually prefer Snark-to-Snark Combat, Usagi has ended up slamming Ijuuin into a wall one time and it may have very well escalated past that had it only been the two of them in the room.
- Deadpan Snarker: He always becomes this to Misaki due to his arrogant personality.
- Declaration of Protection: One of his ultimate determination for Misaki.
- Defrosting Ice King: He used to be a loner until he met Misaki.
- Dirty Old Man: Being older than Misaki by 10 years and having greyish hair, he invokes this greatly when combined with being a general pervert.
- Dull Eyes of Unhappiness: A constant status of his eyes, which is appropriate due to his lonely past and his best friend never takes a hint of his affection.
- Easily Forgiven: Even though he had raped Misaki in the beginning, the latter gets over it so easily and talked to him afterwards as if nothing happened. Granted, Misaki did threaten to expose his sexuality and his hidden affections to Takahiro, which is his biggest fear.
- Emotionless Boy: In the Minimum chapters.
- Gaydar: Invoked a lot, but his accuracy doesn't seem to be 100%, as any men that he detects to be gay turns out to be straight. Of course, in Ijuuin's case it's another story.
- Green-Eyed Monster: He is easily jealous when Misaki pays attention to someone else.
- Hidden Heart of Gold: For all his pervy and possessive behaviours towards Misaki, his general idiosyncrasies, and his utter lack of social skills, more than one character has commented on his kindness. He is also willing to go through great lengths for the sake of those he cares about, especially about Misaki.
- Lethal Chef: He can't make an egg to save his life.
- Lonely Rich Kid: He has a highly successful career and all the money in the world; he can get anything he wished, but it's not like it will satiate his loneliness.
- Meaningful Nickname: It's well known that "Usagi" means "bunny". Considering rabbits' mating habits...
- Manchild: He apears to be this when Misaki first visits his apartment, finding enough toys that would make any child envious. Usagi's actually trying to simulate a child's environment because he wanted to "recreate what normal kids do in their childhood".
- Men Can't Keep House: Like you wouldn't believe. Misaki even pays his rent by doing the household chores.
- Over-the-Shoulder Carry: He has a habit of carrying Misaki in this way.
- No Social Skills: As a result of being a Lonely Rich Kid.
- Not a Morning Person: He is always in the worst mood whenever he's waken up.
- Ridiculous Procrastinator: Which causes an endless amount of grief for Aikawa and Misaki always has to apologize for it.
- Schedule Slip: In-Universe. This is the reason why Aikawa has to be tough on him.
- Settle for Sibling: He had an unrequited love for Misaki's brother before falling for Misaki.
- Unlucky Childhood Friend: To Takahiro.
- Used to Be a Sweet Kid: Played with. He's noted to be kind both as a child and as an adult, but you wouldn't expect someone as strange and perverted as him to be once a polite, demure boy.
- Yandere: He has the potential to become this due to his possessive behavior towards Misaki, with him even saying that he wants to lock Misaki up several times. And it's obvious that he could snap any day now due to his emotional/mental stability relying on Misaki being with him.Usagi: I'd lock you up in a world where you can only see me and not like anything or anyone else but me.
- Younger Than They Look: He is 28 at the start of the story but looks like he's in his mid-thirties due to his grayish hair when compared to the black-haired Haruhiko or Kaoruko.
- When A Jerk Loves A Tsundere
Childhood friend of Akihiko, Hiroki ended up heartbroken when he realized Akihiko would never return his feelings. Fortunately at that moment, Nowaki showed up to sweep him away like a typhoon. He eventually becomes an associate literature professor at Misaki's school, and works under Miyagi.
- Bookworm: He's one ever since his childhood, as he was willing to look up the words he didn't know even if that lead to even more new words. He has such an extensive collection to the point that there are piles of books in his apartment and Akihiko often borrows reference materials from him.
- Cry Cute
- Defrosting Ice King
- Hair-Trigger Temper
- In-Series Nickname: He has two.
- "Hiro-san" which is Nowaki's nickname for him.
- "The Demon Kamijou/Kamijou the Devil", courtesy of his students.
- Perpetual Frowner: One of the many things Miyagi teases him about.
- Poor Communication Kills: If only he had paid a bit more attention to what Nowaki was saying. In general his tsundereness leads to communication troubles regarding his feelings.
- Pride: There is a reason his story is called "Egoist".
- Sadist Teacher: He walks the line between a humorous version of this and the Stern Teacher. He genuinely believes he is being fair and simply has high expectations of the students. On the other hand, he throws chalk and books at them for texting or talking during class, which would probably get him assault charges in real life. They call him "the demon" for a reason.
- Sex Equals Love: He failed out on this one harshly when he slept with Akihiko hoping it would convey his feelings and that Akihiko would love him back. It really didn't. Further zigzagged in regards to his argument that he only sleeps with people he loves, as there are implications that he didn't in the past, and Akihiko and Nowaki are more the exceptions than the rule.
- Snark Knight: He has quite snappy conversations with Akihiko and Miyagi.
- Throw the Book at Them: Nowaki being his most frequent victim, at least in the beginning of their relationship.
- Tsundere: A huge type A.
- Unlucky Childhood Friend: To Akihiko.
Nowaki, found orphaned on the day of a typhoon, started working out of junior high but is determined to enter university. He falls in with Hiroki upon their first meeting and begs him to be his tutor in order to spend time with him. Eventually he realizes both his goals and becomes a pediatrician.
- Beware the Nice Ones: When he thought Miyagi was putting the moves on Hiroki.
- Crazy Jealous Guy: If he thinks that someone is hitting on Hiroki, he suddenly becomes defensive. Akihiko just gets scorned but Miyagi nearly gets punched that one time. Just have a look◊.
- Dogged Nice Guy
- Friend to All Children: His career choice is to be a pediatrician.
- Love at First Sight: He says that he falls in love with Hiroki this way.
- Luminescent Blush: The only seme in the series to gain this.
- The Pollyanna: Played with. Despite being an orphan, supporting himself and dealing with the constant beatdowns he gets from Hiroki, he's always smiling and thinking positive.
- Poor Communication Kills: If only he had told Hiroki more clearly about his plan to study abroad. Or when he was leaving. Or that he was coming back. In general this is a problem for .
- Second Love: For Hiroki.
- Self-Made Man: He is an orphan and has to juggle various jobs to support himself, yet this doesn't prevent him from pursuing his dream of being a pediatric doctor.
- Through His Stomach: He successfully persuaded Hiroki to tutor him partly thanks to his cooking skills.
- Tall, Dark, and Handsome: So tall, dark and handsome that a chance encounter on the train inspires Misaki to go home and begin training to become taller in one of the extras.
An accomplished but somewhat listless literature professor at M. university who is Hiroki's senior. Some time after his wife leaves him following her affair with another man, her little brother shows up in his life demanding that he "take responsibility" because he loves him.
- Absent-Minded Professor: If you enter his office, you will never find your way out. Not without a map.
- Ascended Extra: He was originally meant to be a minor character in the Egoist story, but eventually got his own story because he became so popular with fans.
- Bi the Way
- Bunny-Ears Lawyer: It's hard to believe that he is a prominent figure among literary researchers at first since he hardly works on screen. Hiroki has commented on this.
- His Story Repeats Itself: Miyagi's situation with Shinobu mirrors his story with his teacher in the past, with him switching roles. He is interested in literature because of his teacher, thus becoming her Spear Counterpart.
- Hot for Teacher: His first romance was this.
- Karma Houdini: During the time when Hiroki and Nowaki were having serious problems, Miyagi intercepts a message Nowaki wants to leave for Hiroki to tell him he's going to be late meeting him. Miyagi never passes along this message, and by doing this Hiroki suffers a massive Heroic BSoD and his relationship with Nowaki is almost fractured beyond repair. Yet this isn't ever brought up again, and Hiroki and Nowaki have no idea he did this.
- MayDecember Romance: On both sides of the trope with his two love interests.
- Smoking Is Cool
- Snark Knight
- Stepford Smiler: A mild version. He acts happy-go-lucky and teasing, especially around his junior co-worker Hiroki, but he has been unable to move on since his teacher died.
- Tall, Dark, and Handsome
- The Tease: Towards Hiroki.
On his way to his sister's wedding, he is attacked by punks until Miyagi comes to his rescue. Shinobu thinks it's destiny and they are meant to be together until he finds out that Miyagi is his sister's fiance. When they get divorced he comes back to Japan because that must be destiny.
- Catchphrase: "It's fate".
- Crazy Jealous Guy: Compared to Akihiko and Nowaki, it's mainly played for laughs.
- Deadpan Snarker
- Dogged Nice Guy: It verges on Stalker with a Crush in places when he's trying to get Miyagi to go out with him.
- Expy: He looks like Hisoka from Descendants of Darkness.
- Gratuitous English: YEAH, I WAS ROLLING ON THE FLOOR LAUGHING.
- Hot-Blooded: When he isn't snarking at everything, he's usually yelling.
- Insane Troll Logic: He borders on this when it comes to why Miyagi should be in a relationship with him.
- Insufferable Genius: He is supremely confident that he will get into the best university in Japan... And he's right, even acing every subject in the entrance examinations. That said, though, he seems to continuously hold the Idiot Ball when it comes to relationships. So, in other words, he's very similar to Usagi.
- Just Ignore It/Somebody Else's Problem: He thinks that the problem of their seventeen-year age gap is basically nonexistent, and he doesn't care one bit that he's the son of Miyagi's boss! He also thinks that the fact that Miyagi is concerned about any of this is stupid. Miyagi has a very different opinion.
- Lethal Chef: Besides making cabbages, he can't cook anything else. And he is still working on cooking those competently.
- Meaningful Name: One of his name meaning is "to endure". And now we remember why he's such a Woobie.
- Perpetual Frowner
- Rescue Romance: Fell for Miyagi after the latter rescued him from some street punks on the day of Miyagi and his sister's wedding.
- Second Love: For Miyagi.
- Sugar-and-Ice Personality: Unless it concerns Miyagi, he will not go into deredere mode.
- Teen Genius: He got nothing but perfect scores on his entrance exams. And he was applying in the same university Misaki was struggling to get into.
- Through His Stomach: He tried this tactics to win Miyagi over. However...
The son of a wealthy family that runs a publishing business, which he only entered because he had a knack for it and couldn't hack it as a writer. Crosses into the Romantica storyline as another editor of Akihiko's, and was the person who convinced him to publish as a teenager.
- Beleaguered Assistant: Like Aikawa, he has to deal with Akihiko's idiosyncracies on a regular basis.
- Brilliant, but Lazy: He still gets his work done, but very few people alive have ever seen that process occur.
- Bunny-Ears Lawyer: He's seen more often in Sekai-ichi Hatsukoi than Junjou, but he has some really strange and frustrating... er, "quirks" that constantly leave his staff in a state of heightened irritability. Unfortunately he is just that good, so he's not going anywhere.
- Character Overlap: He appears in Sekai-ichi Hatsukoi as the director of the publishing company the protagonists work for.
- Hidden Depths: He acts goofy and is generally a pain to people around him. But he is smart, very perceptive and can be manipulative when necessary.
- Imaginary Love Triangle: He irrationally assumes Asahina is in love with his father instead of himself.
- Living Emotional Crutch: Towards the end of the Mistake storyline, he proves the reason he keeps Asahina around isn't because he can't take care of himself, but because he is emotionally dependent on him.
- Manipulative Bastard: He didn't get to where he is just by being a great editor, and he borders often on Magnificent Bastard territory when it comes to manipulating other people's lives, as well as screwing with Ritsu's sense of self-worth.
- The Obstructive Love Interest: One of the reasons why their story is called "Mistake".
- Slap-Slap-Kiss: With Asahina... even more than ten years after they get together.
- Smug Smiler: This, combined with his confrontational personality when people complain about his success at work, means he makes a lot more enemies than friends.
As his family was about to commit suicide together due to bankruptcy, Isaka's father found them and hired them, leading to Asahina becoming Isaka's playmate and eventually a sort of caretaker. His gratefulness to Isaka's father leads to Isaka misunderstanding just who he has feelings for.
- Beleaguered Assistant: To Isaka.
- The Comically Serious: He is so poker-faced that at times it makes for a few hilarious moments.
- Gender-Blender Name: Like Misaki and Shinobu, Kaoru is a unisex name.
- Not So Stoic: Despite all of his calmness and maturity, Kaoru completely lost it when he heard that Isaka accepted a matchmaking dinner with another company president's daughter.
- The Obstructive Love Interest: The other reason why their story is called "Mistake".
- Only Sane Man: Alongside Misaki, he's one of the more well-adjusted characters of the main cast.
- Slap-Slap-Kiss: Extensively with Isaka.
- Subordinate Excuse: He became Isaka's assistant because he was in love with him for years but didn't feel like he could tell him.
- Sugar-and-Ice Personality
- Vitriolic Best Buds: Again with Isaka. He's often present to clean up after whatever mess he makes when he's in Manipulative Bastard mode.
Aikawa Eri - Romantica
Akihiko's beleaguered editor.
- Ascended Fangirl: She was a fan of Akihiko before becoming his editor. This can also be considered a case of Be Careful What You Wish For due to her charge being a Bunny-Ears Lawyer.
- Beleaguered Assistant: She has to work with Akihiko, but she is tough enough to cope with her work and even profits from it.
- Beware the Nice Ones: A kind, welcoming and beautiful woman... who hides a fierce streak that is especially visible when Akihiko doesn't respect his deadlines.
- Christmas Cake: Despite being beautiful and successful in her carrier as an editor, Aikawa's zero experience in dating implies her to be this.
- The Chew Toy: She is subjected to this thanks to Usagi often screwing up his deadlines.
- Fag Hag: With the added benefit of being genuinely attractive, somewhat intelligent and very supportive of Akihiko's relationship with Misaki, which makes for a refreshing positive portrayal of this character type.
- Hello, Nurse!: She is actually very beautiful herself.
- Yaoi Fangirl: To a devilish degree! And it is also because of this that she doesn't have the typical Hatedom female characters usually garner in any yaoi series.
Takahashi Takahiro - Romantica
Misaki's elder brother and Akihiko's first love.
- Big Brother Instinct
- Cloud Cuckoolander: He had some strange ideas about how to raise Misaki.
- Oblivious Big Brother: He doesn't seem to be aware that his brother and his friend are an item.
- Oblivious to Love: He was unaware of Usagi's feelings for him for ten years.
- Promotion to Parent: Misaki is well aware of how much his brother has sacrificed for him.
Usagi's older half-brother.
- Beneath the Mask
- Cloudcuckoolander: Almost all his interactions with Misaki screams this.
- I Want My Beloved to Be Happy: Eventually adopts this attitude, even stating that while he still won't give up on Misaki, he'll no longer push his feelings on him. He even states that he's glad he fell in love with Misaki, one-sided his affections may be.
- Not Blood Siblings: He and Akihiko have different mothers. His mother was their father's lover.
- Missing Mom: He was taken into the Usami family when he was in junior high school after his mother's death.
- Not So Different: After talking with him, Misaki believes that despite how different they look or how much they may dislike one another, he and Akihiko actually have a lot more in common than they think.
- Stoic Spectacles
- Sugar-and-Ice Personality: He seems like he has no emotions whatsoever, but later chapters reveal that he may actually be in love with Misaki, and is willing to do anything to make sure that Misaki is happy.
- Tall, Dark, and Handsome
Usami Fuyuhiko - Romantica
Father of Akihiko and Haruhiko. Married into the Usami family.
- Awful Wedded Life: Enough so that his wife took her frustrations out on their son; thus why Akihiko tries living his missed normal childhood and one of the reasons why Fuyuhiko is trying to re-bond with his son.
- Bitch in Sheep's Clothing: Despite being all smiles, he went from constantly trying to guilt-trip Misaki into leaving Akihiko, to outright telling him his existence is a hindrance then getting him to doubt his self-worth.
- Papa Wolf: It's obvious he cares very much for his sons and tries to do whatever he can to keep them from being hurt. However, he can be a real Jerkass about it. When he learns Haruhiko has feelings for Misaki, he tricks Kaoruko into coming back to Japan so the two could be engaged and; despite knowing Akihiko's feelings for Misaki (and being told to stay out of his business), Fuyuhiko still brings match-making photos for brides. His excuse? He knows what's best.
Usami Kaoruko - Romantica
Akihiko's cousin who takes an interest in Misaki.
- Because You Were Nice to Me: The reason she begins to like Misaki is because he's the first person who ever encouraged her to follow her dreams.
- Belligerent Sexual Tension: There's more than one reason why she demands Mizuki constantly act as her gopher despite the fact they always argue.
- Clingy Jealous Girl: Subverted, in that while she makes it obvious she likes Misaki and will demand he spend time with her whenever he can (even that he come back to France with her), she doesn't try to forcefully break Akihiko and him up, and Akihiko lets them spend time together, which is saying something.
- Crazy-Prepared: In her first appearance, she brings briefcases filled with stuffed bears plus a mechanical bear to bribe Akihiko to let her stay at his apartment.
- Kimono Fanservice: A Type B example.
- Kissing Cousins: She was engaged to her cousin Haruhiko (though due to the Usami Tangled Family Tree is not actually related to him), then demanded her other cousin Akihiko wed her instead to break off the marriage her parents tried to force her into. But she liked Misaki better. And according Mix 5: Mizuki seems to have moved on to her cousin, Mizuki.
- Odd Friendship: She seems to have formed one with Ijuuin, even inviting him to come with her to France.
- Supreme Chef: She eventually becomes good in baking when Misaki encourages her to pursue her dreams of being a pastry chef.
- What the Hell, Hero?: Mizuki isn't a hero or a nice guy by any stretch, but at one point Kaoruko chews him out for his treatment of Misaki, combined with a good whack on the head.
- Yamato Nadeshiko: Played with. See the kimono entry here for why she fits and the Tsundere entry for why it's not a perfect fit.
Ijuuin Kyou - Romantica
Creator of The Kan, Misaki's favorite manga.
- The Cameo: During the New Years Eve party in Sekai-ichi Hatsukoi.
- Did Not Get The Guy: Misaki's answer to Ijuuin when they meet at Kamakura leads to tropes further below.
- Erotic Dream: The extra chapters centered around Ijuuin reveal that he occasionally has these, with Misaki in the dream of course.
- To Akihiko. Akihiko has light hair and eyes, and typically wears suits while Ijuuin has dark hair and eyes, and dresses casually (the times we do see him in a suit, there's even a contrast in their suit colors). Their work ethics and attitudes toward their work also sharply differ: Ijuuin tries to keep to his schedule in order to not to disappoint his fans with delays even if he himself isn't satisfied with the quality, while Akihiko will constantly procrastinate in order to get over a writer's block, even if it means pushing his deadlines back. And though Ijuuin has become slightly disillusioned some of his fans like him rather than his works, he still likes meeting them; there's no doubt readers enjoy Akihiko's books due to winning awards, he'll try to escape congratulatory ceremonies as soon as possible. Unlike with Akihiko, Misaki reads Ijuuin's works religiously and has no problem openly declaring his "love" for him. While it may not have been the same person, both men had fallen in unrequited love with a Takahashi; Usagi with Takahiro and Ijuuin with Misaki.
- Haruhiko as well. Their run-ins with Misaki seem to happen at the randomest moments, they shower him with gifts (quite literally in Haruhiko's case) and Misaki cheered them on into continuing their creative paths, Haruhiko with his architecture and Ijuuin during his slumps. Both men are in love with Misaki, stating before that they wanted to steal him away from Akihiko, and eventually were clearly rejected by Misaki. Contrast how they handled it- while Haruhiko still couldn't give up his feelings, what was most important to him was Misaki's happiness. Later in the manga, he told Usagi not to worry about him trying to go after Misaki anymore and even warned of their father possibly trying to tear them apart. With Ijuuin- it wasn't until others had to warn him of the consequences of continuing to pursue Misaki even after being rejected that he finally stopped; though unlike Haruhiko, it's obvious that Ijuuin doesn't want their relationship to last.
- He Cleans Up Nicely: He looks like an absolute wreck whenever the deadlines for his manga are near (think of the Emerald guys from Sekai-ichi Hatsukoi during the last days of their cycle), but is actually very, very handsome.
- Hopeless Suitor: Though Misaki very clearly rejected his confession, Ijuuin told Usami to his face he wouldn't give up and if he ever saw Usami had upset Misaki, he'd steal Misaki away.
- Hyper-Awareness: As seen in Sentiment, he could already tell that Misaki and Akihiko were a couple and in Mix 5: Mizuki, he reassures a jealous Mizuki there's nothing to worry over his visit to Kaoruko in France; Kaoruko returns Mizuki's feelings.
- Innocently Insensitive: He comes on really strong to Misaki one time too many that it comes off as creepy. He doesn't seem to be aware that he's actually making Misaki more and more uncomfortable however, and when Mizuki and Akihiko actually point it out to him, he stops his pursuit.
- Love at First Sight/Love Epiphany: What he claims his first meeting with Misaki at Marukawa Publishing was.
- Love Confession: He gives one to Misaki in Chapter 31.
- Men Can't Keep House: When Misaki goes to drop off some gifts to Ijuuin's apartment, he's warned about how messy it will be. While it is indeed messy, Misaki's seen worse...
- Nice to the Waiter: He's kind to every one of his fans and genuinely appreciates their support, even keeping fan letters that are already years old.
- No Sense of Personal Space: Towards Misaki to the point that even he can tell something's off.
- Odd Friendship: He develops one with Kaoruko.
- Older Than They Look: It hasn't been established exactly what Ijuuin's age is, but according to a flashback in Sekai-ichi Hatsukoi, Yuu Yanase and Chiaki Yoshino were reading The Kan back in middle school, which was 15-16 years ago. Ijuuin would have to had been high school aged at the very least to successfully publish a manga story, so he's around his mid 30's at least.
- Red String of Fate: They first encountered each other when he was in a slump and Misaki gave him a pep talk, then they meet again three years later at the autographing session. He believes it to be fate, at least.
- Rejection Affection: Turns it into a Type 4 Triang Relations. He eventually stops when Mizuki warns him that if he doesn't draw a line soon, Misaki might end up hating him.
- Ship Tease: There seems to be a bit of this between him and Yuu Yanase from Sekai-ichi Hatsukoi.
- Snark-to-Snark Combat: Almost every time he and Akihiko meet. This shows especially during their interview where they're asked about their thoughts on each other's works.
- Stalker with a Crush: His first few run-ins with Misaki really could have been coincidence, but the increasing frequency of which he just so happens to now is a bit... suspect.
Tsumori - EgoistNowaki's senpai and friend in the same hospital he works in. Hiroki doesn't like him very much.
- The Gadfly: His clingy antics on Nowaki always irks Hiroki.
Takatsuki Risako - Terrorist
Shinobu's older sister and the former wife of Miyagi.
- Amicable Exes: Though she and Miyagi are divorced, they're not on bad terms with the other, and mutually agree that their marriage wouldn't work out in the first place.
- Feminine Women Can Cook: Unlike Shinobu, she took cooking classes.
- Old Flame Fizzle: After divorced with Miyagi and went out with many other men, Risako discovers that Miyagi is indeed a very good man. Too bad that Shinobu is now the holder of Miyagi's heart.
Todo Shinnosuke - Romantica
Misaki's fellow classmate and friend that he made over their shared love over The Kan. He attends Mitsuhashi University as a Law student in order to become a police officer.
- Adorkable: Whenever he goes into fanboy-mode.
- Badass Bookworm: He's Misaki's tutor for Kamijou's class and a part of the kendo team.
- Commonality Connection: He and Misaki instantly bond over their love for the same manga.
- Imaginary Love Triangle: Usami is convinced Shinnosuke is acting the part of the innocent guy who'll steal Misaki away, even though for once this isn't the case.
- Nice Guy: He easily gets along with Misaki, providing him with support in both his personal life and his studies. And he's one of the few people who approaches and befriends Misaki without any ulterior motives.
- Only Sane Man: He has the honor of being the only one who can honestly say he's unrelated to the entire madness.
Shiiba Mizuki - Romantica
Another of Akihiko's cousins (from his father's side this time) that suddenly reappears after living abroad. While clingy to Akihiko, he's hostile towards Misaki for some reason.
- Aww, Look! They Really Do Love Each Other: Figuring there's no way someone like him could win her over, it's not until Mizuki reveals to Kaoruko that he wants to give up on her that she drops the major hint his feelings aren't unrequited.
- Crazy Jealous Guy: As he puts it, "Everything she likes drives me crazy!"
- Jerkass: His smug attitude rubbed Misaki and fans alike the wrong way.
- Jerkass Has a Point: He may be an asshole, but his berating is what causes Misaki to give serious thought towards his future.
- HeelFace Turn: Not that he was evil, just a jerk, but quits clinging to Akihiko in order to make Misaki jealous, and we learn his real reason for coming back to Japan was to spy on Akihiko and Misaki's relationship for his uncle Fuyuhiko.
- Kissing Cousins: It's implied his hostility for Misaki is because he has feelings for Akihiko though it's actually over Kaoruko that drives him to be so nasty.
- Pet the Dog: He normally treats Misaki badly, but Mizuki does come to his defense when he tells Ijuuin that he's making Misaki uncomfortable by constantly coming on to him even after Misaki made it clear that he doesn't reciprocate his affections.
- Tsundere: It seems to be obvious to everyone except Misaki the reason why Mizuki is picking on him and arguing with Kaoruko. He gives his phone number to Kaoruko in case she ever wants to talk and agrees to be swap numbers with Misaki.
- What the Hell, Hero?: Ijuuin's not a hero, but he is by no means a bad guy so this still counts. After a brief but tense confrontation between Ijuuin and Kaoruko regarding the former's feelings for Misaki, Mizuki calls Ijuuin out on the way he's been pursuing Misaki with a speech reality-checking enough to make him finally back down.Mizuki: I understand where you're coming from, but aren't you ignoring [Misaki's] feelings? If the guy you love says he likes another guy, shouldn't you give up and wish for his happiness? If you don't want to give up, why don't you not interfere, be patient and wait for your chance? After that is questionable, but if the guy you love comes to hate you, be prepared for your defeat.