- Adorkable: Emphasis on the "dork" bit.
- Accidental Pervert: Don't know how "accidental" as Makoto gets throughout the series.
- Catch Phrase: A "Here I go!" or something similar whenever he is about to, ahh, engage Yura.
- Chick Magnet: Pretty much the entire female cast has shown at least fleeting interest in him, with some having outright obsessions. Especially weird given that he's married.
- Clueless Chick Magnet: Naturally, he never picks up on any of them.
- Christmas Cake: A rare male example at the very beginning. He's 25 years old, does quite well for himself at his job and is seen as attractive by most women, but he's still a virgin and terrified of remaining one. Luckily, he meets Yura not long after.
- Genius Ditz: He's actually quite competent at his job and is something of a rising star in the office. When it comes to everyday affairs, particularly romantic ones, he's completely clueless.
- Good Angel, Bad Angel: Had at least one visit from them.
- Happily Married: To Yura. Maintaining a stable marriage is the focus of the story.
- Idiot Hero: Far from the sharpest tool in the shed, almost always thinking about sex, and often fails to consider Yura's feelings. Still a good guy, though.
- The Loins Sleep Tonight: You just can't win 'em all, Makoto. (Actually, he can't win most of 'em, because when he can get it up, more often than not he can't last a full minute. This continues past their first wedding anniversary.)
- Man Child: Despite being 25 at the beginning of the series he still clearly acts like he thinks he's still in high school.
- Nice Guy: He's thickheaded, but he tries his best to be a good husband and friend.
- Oblivious to Love: Flipside to his Chick Magnetism.
- Red Oni, Blue Oni: The red to Yura's blue.
- Thanks for the Mammary: Manages to get himself in this position often.
- This Loser Is You: In spades; the "narration" boxes have a particular tendency to make fun of his one-track mind and occasional bouts of Insane Troll Logic.
- Buxom Is Better: Her endowment, which fills a Japanese E-cup bra (roughly a D in American sizes), is the target of much admiration, from both sexes, throughout the series.
- Christmas Cake: Narrowly averts this, as she meets her soon-to-be husband Makoto when she is twenty-five years old.
- Closer to Earth: She's not as clueless about life and romance than Makoto, though she's still pretty clueless.
- Cool Big Sis: To Jun.
- Dude Magnet: Though unlike women with Makoto, men tend to simply grumble to themselves about how she's taken.
- Extreme Doormat: Has problems speaking her mind and standing up for herself, even to Makoto. She's gotten better over time though.
- Happily Married: To Makoto. The story focuses on maintaining one.
- House Wife: Becomes one after marrying.
- Hurricane of Euphemisms: Frequent target of this (usually from Rika), being inexperienced with sex and fairly innocent.
- My Girl Is Not a Slut: She grow up with this mentality, unlike her far more loosed up sister and after getting married, she had inicial troubles dealing with her new discovered sex drive. She gets better.
- Red Oni, Blue Oni: The blue to Makoto's red.
- This Loser Is You: Although she screws up much less than Motoko.
- Yamato Nadeshiko: Quits her job after marrying her husband, polite, demure and very beautiful. She ticks all of the boxes.
Mamoru OnodaMakoto's father.
- Butt Monkey: Has a habit of walking in on or overhearing his children having sex, which obviously makes him uncomfortable.
- Closer to Earth: Inverted. He's much more reasonable than his wife is.
- Only Sane Man: He's the most stable of the Onoda's.
Akiko OnodaMakoto's mother.
- I Want Grandkids: Whenever she gets in contact with Yura, she'll always drop the hit that there's still no babies in her marriage, and would blame Makoto's bed skill. She even asked Kyouko to get in the picture so she could make sure they have babies.
- Let Her Grow Up, Dear: While her husband was in shock on Jun's love life and was all about "Girls must remain maidens until marriage", she was more interested in how was her affairs and even points how she wasn't a virgin neither when she married him.
- Obnoxious In-Laws: Downplayed. She mostly is obnoxious when there's hints of a possible pregnacy and in other cases, she's obnoxious to her own son because she wants him to improve.
Akira OnodaMakoto's big brother.
- Big Brother Bully: Played for Laughs. He genuinely wants to help, but keeps butting incessantly in Makoto and Yura's sex life to give them "advice" that they don't even really want in the first place.
- Big Brother Mentor: How he sees himself.
- Chivalrous Pervert: Presents himself as one, though how chivalrous he is can be debated.
- Large Ham: Very large.
- No Indoor Voice
Sanae OnodaAkira's wife.
- A-Cup Angst: She's even smaller than Jun, who's still developing, and her husband's attitude that Buxom Is Better just makes it worst.
- Cool Big Sis: She's a better sex mentor to Yura than her husband is to his brother.
- Tsundere: She may love her husband but always has to hold him back everything he's admiring Yura's...and Rika's, and even Jun's beauty.
Jun OnodaMakoto's little sister.
- First Guy Wins: After having some adventures mentioned below, finally makes an emotional connection with an e-mail pal. It turns out to be her first love, Inoue.
- Horrible Judge of Character: in her search for true love, she manages to
a) have a one-night-stand with a man she practically just met (who — shock! — turns out to have a girlfriend), right after breaking up with her boyfriend because she feels their relationship has lost the spark,
b) become the (oblivious) fifth sex-friend of an obvious playboy (despite the warnings of her best friend, she is devastated upon seeing him enter a love hotel with another girl) and
c) pursue an affair with a homely middle-aged married man, this time mere hours after first talking to him. One can almost not blame her father for calling for a family conference about her behavior...
- Looking for Love in All the Wrong Places: See Horrible Judge of Character above.
- Wide-Eyed Idealist: That turns her into The Ingenue.
Kyouko OmiyaMakoto's cousin.
- But I Read A Book About It: She's a OB/gynecologist who knows about sex theory but as a virgin, has no practical knowledge.
- Christmas Cake: Firmly entrenched in this trope (and boy does she know it). That is, until Matsuzaki came along.
- My Girl Is Not a Slut: Kyoko is 30 years old and still maiden. In a Gender Flipped version of A Man Is Not a Virgin, this causes her anxiety.
- Tsundere: She's just as likely to Dope Slap Matsuzaki upside the head as she is to give him (perfectly genuine) passionate doe-eyes.
Hideki KawadaYura's father.
Chiharu KawadaYura's mother.
- Absurdly Youthful Mother: At 46 years old, she looks so young that she could pass of as her daughters' sister to strangers.
- Meganekko: Of the Stoic Spectacles type.
- Silk Hiding Steel: Chiharu is elegant and composed, but has a sharp tongue that can spit venom.
Rika KawadaYura's little sister.
- A-Cup Angst: In a scene where she bathes with her sister Yura and their mother, she gets angry after noticing that, unlike Yura, she hasn't inherited her mother's big breasts.
- Good Bad Girl: She's a fairly nice girl who happens to be very assertive about her sexuality. This makes her be the Big Little Sister to Yura in sex matters.
- My Girl Is a Slut: Sleeps with other men besides her boyfriend. When she suspects her boyfriend to be cheating on her with other women, it is pointed out that she does the same thing.
- Really Gets Around
- We Named the Cat Yamada: Names her cat after her boyfriend.
- It Must Be Mine: The reason why she only sleeps with married men is because she's the type of person that wants what other peoples have. That's her whole deal with wanting Makoto to cheat on Yura with her.
- Your Cheating Heart: Makie constantly tries to get Makoto to have an affair with her. She genuinely doesn't think adultery is wrong going by the crazy arguments she uses to support her beliefs.
Mai Nagao and Ikuyo Tonegawa
Manabu Okahama (the buckteeth one) and Yosaku Inagaki (the sour face one)
- Casanova Wannabe: Okahama. Inagaki, meanwhile, has pretty much accepted that he'll never find a woman that's interested.
- Deadpan Snarker: Inagaki. Given his two best friend's personalities, it's understandable.
- Heterosexual Life-Partners
- Hot-Blooded: Okahama has a tendency to get pretty passionate.
- Stalker with a Crush: Okohama is absolutely obsessed with Yura and will hit on her, or indicate his desire to do so, whenever he appears.
- Those Two Guys
- Red Oni, Blue Oni: Okohama is manic and excitable while Inagaki is sullen and snarky.
- The Stoic: Inagaki.
- Aloof Dark-Haired Girl
- Attempted Rape: Suffers one of this in chapter 139 after getting really drunk in a meet-up date. She was saved by Makoto, Yura and Rika.
- Does Not Like Men: Turns out she's actually Makoto-sexual.
- Foil: To Rika. Chapter 139 is dedicated to their opposite personalities.
- The First Cut Is the Deepest: The cause of her crush on Makoto.
- Glamorous Single Mother: She wants to have a baby without having sex. Her one track minded co-workers insist that's impossible. Obviously nobody considers artificial insemination or adoption.
- Mistaken for Gay: Since she has no interest in men and sex, a lesbian co-worker then assumes she's a lesbian as well. She tries to convence everybody that she's not gay with no results.
- She's All Grown Up: She was plain looking and dressed poorly as a teen. As an adult she's beautiful.
- Tsundere: She has a crush on Makoto, but is frequently annoyed with him.
- Unlucky Childhood Friend
- Bishōnen: Accompanied by plenty of Bishie Sparkle.
- The Casanova: Matsuzaki is definitely a playah, though his antics usually don't work on several women in the story.
- Chivalrous Pervert: He's a serial womanizer, but he's a decent guy.
- Dark-Skinned Blonde
- Does Not Like Men: His goal in life is seducing women, so he finds men to be either annoyances or rivals. He comes around to Makoto later on, and even seems to warm up to Okahama and Inagaki as well.
- Henpecked Husband: When he starts dating Kyouko, he's forced to do everything she tells him to do while only responding with simple "Yes dear"s.
- Jerk with a Heart of Gold: See Chivalrous Pervert. He's also somewhat hostile to Makoto most of the time but is ultimately willing to hang out as friends with him.
- Ladykiller in Love: His crush on Kyouko.
- Likes Older Women: Well, more like likes more experienced women.
- Sharp-Dressed Man: He's an impeccable dresser with a wardrobe consisting of crisp suits and polo shirts. Especially noticeable compared to the otherwise plainly dressed male cast.
- Stalker with a Crush: Has some vibes of this in his efforts to win over Kyouko. The fact that she exploits him as a chauffeur at first just makes their eventual hook-up that much creepier.
- Unknown Rival: To Makoto initially.
- Abhorrent Admirer: She's not ugly, but the object of her affections isn't a lesbian.
- Incompatible Orientation: With Miyuki.
- Lipstick Lesbian
- Satellite Character: For Miyuki.
- Single-Target Sexuality: With Miyuki.
- Stalker with a Crush: A light example towards Miyuki.
Mika and Takashi Yabuki
- Babies Ever After: The last few chapters with them have Mika telling Yura that she's pregnant.
- Cleopatra Nose: Takashi has a rather prominent nose, though he's still rather handsome.
- Ojou: Takashi commented that Mika comes from a wealthy, conservative family.
- Sexless Marriage: They didn't have sex in over a year, which frustrates Mika. Turns out to be medical condition on Takashi's part.
- Huge Guy, Tiny Girl: The Tiny Girl to her husband, Ken.
- Older Than They Look: She's in her early twenties, despite looking like a little girl. Her age being frequently reminded in the narration serves as a Running Gag.
- Face of a Thug: Makoto mistook him for a yakuza when they first met.
- Gentle Giant: He is very mild-mannered and polite.
- House Husband: The one who does all the housework, especially since his wife dislikes doing it.
- Huge Guy, Tiny Girl: The Huge Guy to his wife, Shoko.
- Gossipy Hens: A typical talkative housewife.
- Daddy's Girl: After her parents got divorced, she stayed with her father and this definitely formed her. When her mother comes to offer her to leave her father and move in with her, Rui decides to stay with her father and finally fully accepting Kayo as his lover and her (future) Stepmother.
- Hot for Teacher: She has a huge crush on her teacher Watanabe.
- Happily Married: He begins a romance with Kayo and ends up marrying her.
- Pervert Dad: Has a habit of peeking on his daughter in improper situations, due to sexual frustration.
- All Women Are Lustful: Turns out she absolutely loves sex and is not above experimenting with things, including bondage.
- Happily Married: Her second marriage, to Rui's father Hisao, is very happy compared to her first one.
- Noodle Incident: For a long time, she frequently compared things to her previous marriage, then begins muttering to herself how this may have or may have not been a reason why her marriage failed... without ever really mentioning what exactly she means, leaving people wondering.
Taku YamadaRika's boyfriend.
- Bastard Boyfriend: He's only interested in Rika when he wants sex and cheats on her multiple times. Not that Rika is any better.
- Jerk with a Heart of Gold: An extreme case who will basically only be a nice person if he has no other choice.
- Making Love in All the Wrong Places: When he wants some, he will have it, no matter the place.
- Slap-Slap-Kiss: With Rika, to the point one wonders if they have other thing in common aside the good sex.