The series' protagonist, a 25-year-old elite salaryman for a foreign cosmetics maker.
- Adorkable: Emphasis on the "dork" bit.
- Accidental Pervert: Don't know how "accidental" as Makoto gets throughout the series.
- Catchphrase: 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.
- 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.
- Clueless Chick Magnet: Has no idea that he's the object of multiple women's affections, even in cases where it's blatantly obvious.
- 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.
- Large Ham: Some of his reactions are over-the-top, especially when he has a hilarious mini-Heroic BSoD whenever Yura tells him she doesn't feel like having sex right now.Makoto: *in the depths of despair* You don't like me...Yura: What? That's not it...Makoto: You don't like my wieney...!
- Manchild: 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: Despite being a Chick Magnet he never seems to pick up on the signals of a large number of females who have been crushing on him. In fact, he will never figure it out unless a woman directly propositions him.
- Salaryman: One of Japan's typically overworked white-collar corporate drones, though at least he's risen to a decent pay grade.
- Speed Sex: Makoto's biggest issue is that, while he can "get ready" pretty quickly, more often than not he can't last a full minute without ejaculating, which leaves Yura unsatisfated. This continues past their first wedding anniversary.
- Thanks for the Mammary: Somehow always ends up groping someone's breasts by accident.
- This Loser Is You: To some degree Makoto is supposed to represent the uneducated male reader. The "narration" boxes have a particular tendency to make fun of his one-track mind and occasional bouts of Insane Troll Logic.
The Deuteragonist, Makoto's wife. Formerly a travel agent, now a full-time homemaker.
- Beware the Nice Ones: She's slow to anger, but when she finally does... prepare for the most terrifying Tranquil Fury of all time.
- 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: Advises her younger sister-in-law Jun as an experienced mentor.
- Dude Magnet: Attracts lots of male attention, though unlike women with Makoto who refuse to give up, 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. She briefly got a job as a waitress because she wanted to try working again, which made Makoto jealous, but by the end of the chapter she decided that she was content being a housewife after all.
- 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 promiscuous sister and after getting married, she had initial troubles dealing with her new discovered sex drive. She eventually learns to embrace her sexuality more and cherishes how lovemaking lets her feel close to Makoto.
Makoto's father, a perpetual worrywort.
- 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.
- Nervous Wreck: Worries himself sick about just about everything, especially the chastity of his womenfolk.
- Only Sane Man: The most stable of the Onoda family, which isn't saying much.
Makoto's mother, who takes great interest in her son's marriage and is hoping for grandchildren.
- 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 about 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.
Makoto's big brother, a lawyer with a loud mouth who thinks it's his job to stick his nose in Makoto and Yura's business, and lecture them about lovemaking techniques with no regard for who's listening.
- 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: Sees himself as responsible for teaching Makoto the ropes of sex, although his mentorship is sometimes a tad misguided.
- Chivalrous Pervert: Presents himself as one, though how chivalrous he is can be debated.
- Large Ham: Gets extremely loud and passionate when discussing sexual technique or his opinions.
- No Indoor Voice: Tends to shout whenever he gets worked up, and ends up embarrassing his companions by lecturing about sex at the top of his voice in public.
- 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 worse.
- 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.
Makoto's little sister, who is innocent but curious about sex.
- 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: Truly wants to find true love and a stable relationship, but because of her poor judgement she ends up sleeping with a bunch of different guys who turn out to be using her.
- Wide-Eyed Idealist: Has an incorrectly idealized idea of what sex and true love are supposed to feel like, and doesn't realize how many sleazy guys would trick a girl just to get into her pants.
Makoto's cousin, a gynecologist who has a lot of theoretical knowledge about sex but has never had it herself. She frequently advises Yura and Makoto, but her own love life increasingly comes into focus.
- Aggressive Submissive: Bosses Matsuzaki around in day to day life, but becomes submissive as a kitten when they're making love.
- Big Ol' Eyebrows: Has unusually large eyebrows for a girl, which signify she's a Tomboy.
- 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: Kyoko is 30 years old and still maiden, which makes her anxious that she'll never lose her virginity or find a man. That is, until Matsuzaki came along.
- Tsundere: She's just as likely to Dope Slap Matsuzaki upside the head as she is to give him passionate doe-eyes.
- Your Cheating Heart: On one occasion he has sex with an office lady from work and Chiharu finds out, which makes her throw him out of the house and declare her intention to divorce him. He feels remorse and desperately tries to earn her forgiveness. In the end they make up with each other.
- Meganekko: Of the Stoic Spectacles type.
- Mum Looks Like a Sister: At 46 years old, she looks so young that she could pass of as her daughters' sister to strangers. This is because she got pregnant with Yura when she and Hideki were in college.
- Silk Hiding Steel: Chiharu is elegant and composed, but has a sharp tongue that can spit venom.
- 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: Oh, yes! She's introduced with having multiple sex-friends next to her steady boyfriend and those are just the ones she regularly sleeps around with.
- We Named the Monkey "Jack": Names her cat after her boyfriend, "Yamada".
- Insane Troll Logic: Comes up with some pretty flawed arguments to justify adultery.
- 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.
- Meganekko: An attractive glasses-wearing woman, she is far less innocent than her look suggests.
- 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.
- 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: Since neither of them have any lady luck, they're stuck with each other.
- 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: Always seen as a pair, and never important to the plot except as comic relief.
- Red Oni, Blue Oni: Okohama is manic and excitable while Inagaki is sullen and snarky.
- The Stoic: Inagaki.
- Aloof Dark-Haired Girl: A black-haired beauty who doesn't easily let others get close to her.
- 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: Contrasts with the free-spirited and promiscuous Rika by being more prudish and straight-laced. Chapter 139 is dedicated to their opposite personalities.
- The First Cut Is the Deepest: The cause of her crush on Makoto.
- 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: She always loved Makoto, but he never figured it out and ended up marrying Yura instead.
- 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.
- 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.
- Your Cheating Heart: Tired of being henpecked, he was planning to have a One Night Stand, but ultimately decided against it... after he had already slept with one of his co-workers. Kyoko was not happy about that news. But she did forgive him, while telling him to never do it again, especially since she just found out she's pregnant.
- Abhorrent Admirer: She's not ugly, but the object of her affections isn't a lesbian and wishes she would stop bugging her.
- Incompatible Orientation: She's infatuated with Miyuki, who is straight and only loves Makoto.
- Informed Attribute: Since she never expresses attraction to anyone except Miyuki, and we know about none of her previous relationships, we are told that she is a lesbian without really seeing the evidence for ourselves.
- Lipstick Lesbian: A normal-looking feminine woman who happens to be lesbian.
- Satellite Character: Not characterized in her own right, but rather in relation to Miyuki.
- Single-Target Sexuality: Although supposedly a lesbian, she is never seen being attracted to anyone but Miyuki.
- Stalker with a Crush: Acts very clingy towards Miyuki, although she's mostly harmless.
- D-Cup Distress: The author uses her to illustrate every problem a woman with large breasts could possibly have, from sore shoulders, to difficulty finding bras or blouses that fit, to unwanted male attention, to people making assumptions about her personality.
- Gag Boobs: Her breasts are so huge that they seriously inconvenience her, and create a lot of physical comedy through Funbag Airbag and the usual slapstick gags.
- Shrinking Violet: She's quite shy and has a hard time speaking up for herself.
- Sibling Yin-Yang: She has a younger sister who has the same large breasts, but is the complete opposite of her - she's outgoing, blunt and very open with her sexuality, having lost it in her teens.
- Babies Ever After: The last few chapters with them have Mika telling Yura that she's pregnant.
- Ojou: Takashi comments that Mika comes from a wealthy, conservative family.
- Sexless Marriage: They haven't had sex in over a year, which frustrates Mika. Turns out Takashi had erectile dysfunction caused by stress from work, which was remedied with viagra when he admitted he had a problem.
- 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.
- Accidental Pervert: While he might have some Pervert Dad tendencies, a couple of those peeking incidents were legitimately accidental.
- 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.
- 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.
Jun's first and current boyfriend.
- Highschool Sweethearts: With Jun during Highschool. They get back together after some time.
- Hormone-Addled Teenager: The main reason Jun broke up with him was because he lacked on the romantic end of the relationship after their first time and only was thinking about sex. His response at the break up? He asked for a "Goodbye Sex". He eventually grew out of this phase during their time apart.
- Satellite Love Interest: He only appears when the chapter is focusing on Jun's sex life.