SEX

From left to right: Kaho, Yuki, Female Yuki and Natsu

SEX is a cult classic manga by Atsushi Kamijou, that was serialized between 1988 and 1992. Contrary to the title, it contains no sex at all (it's not without fanservice, though). "Sex" refers to the meaning of "gender" here.

The place is Japan and the time is The Eighties. Kaho is your not so average high school girl who, when her class goes on a school trip to Okinawa, seizes the opportunity to look for her childhood friend, Natsu, whom she hasn't seen in six years. But instead of Natsu she finds a strange young man named Yuki, a petty criminal who takes her for a ride in a stolen car, gets her involved in a gang fight and almost gets her killed. As it turns out, he's Natsu's friend, and the two of them seem to be involved with gangs and live from smuggling and selling stuff in the black market. Kaho is not one to be easily intimidated, though, and the manga chronicles the trio's adventures in Okinawa and Fussa, involving high school delinquents, weirdos, heists, the US army, the Korean maffia, yakuza, even more yakuza, and a shady assassin.

With its stylish artwork, movie-like atmosphere and quirky, charismatic characters, SEX is often regarded as Atsushi Kamijou's best work. That's What She Said...

Tropes associated with SEX (Tee hee!):

Artistic Age: Natsu and Kaho are only sixteen. Yuki may or may not be this case as his age is unknown and can be anywhere between twenty and thirty (what we know of his past suggests that he's definitely over 20).
Art Shift: The artwork often shifts into a more realistic style.
Author Appeal: Kamijou obviously has a thing for high heels. And he's a butt person.
Badass: Yuki, Higa and Female Yuki. Natsu starts out as one, but he becomes stuck in Yuki's shadow in later volumes.
- Badass Long Hair and Badass Longcoat: Higa.
Butt Monkey: Chiaki.
Career Killer: Female Yuki is an assassin. Also, the yakuza hitmen.
Comic Trio: Yuki and Kaho are the weird ones, Natsu is the Straight Man.
Delinquents: A bunch at Natsu's school. Natsu himself is a delinquent as well, but he doesn't display the stereotypical traits except for bleaching his hair.
Distaff Counterpart: Female Yuki. (Not without a reason.)
Dude in Distress: Natsu in the last volume. He's not particularly distressed about it, though, until his kidnapper threatens to kill him.
Drives Like Crazy: Yuki. It doesn't help that he's colorblind and can't tell red and green apart.
- Captain Crash: He has a tendency to crash the vehicles he drives. (He never claimed to be a good driver, though.)
The Eighties ...in Japan.
- The 'dos and the outfits are probably the only things about the manga that haven't aged well.
Mr. Fanservice: Yuki, Natsu and Higa... but especially Yuki.
Even the Girls Want Her: Kaho - detailed in the Les Yay section.
Femme Fatale: Kaho is not quite there yet, but she has great potential to grow up to be one, hampered only by her laid-back and cheerful disposition, and her tendency to be downright weird.
Gratuitous English: By the American soldiers. Also Yuki whenever he talks in English.
Hello, Nurse!: Kaho manages to have this effect on an entire small town.
Identity Amnesia: Yuki.
Innocent Cohabitation: Yuki, Natsu and Kaho end up living together, and are often shown walking around in various states of undress, there's playful flirting and groping (OK, so it's not that innocent) but apparently nothing more happens. Natsu and Kaho take a bath together once but they're fully clothed, and at one point Yuki and Kaho sleep together - just sleeping.
Invisible Parents: Kaho's and Natsu's parents are sometimes mentioned but they don't ever show up and are not involved in the story (only as invisible plot devices).
Katanas Are Just Better: Higa's modus operandi. Sort of justified since he's a Yakuza miniboss.
Kavorka Man: Women flock to Chiaki, for some reason.
Les Yay: In spades between Kaho and Female Yuki who is heavily implied to be in love with Kaho.
- Also present between Kaho and Chigira.
- And one of Kaho's female school mates is very much attracted to her in a one-sided Romantic Two-Girl Friendship way.
Long-Haired Pretty Boy: Higa.
- He's also a Dark-Skinned Blond (though his dark skin is just a tan).
Meaningful Name: 'Natsu' means 'summer' which is one of the main themes of the manga.
Mad Bomber: Natsu is not particularly unstable (in fact he's the Straight Man of the trio), but he has an affinity towards bombs and other explosives.
Male Gaze: In spades.
Ms. Fanservice: Female Yuki is this(although due to the art style she often comes off looking pretty masculine). Kaho becomes this in later volumes.
Mistaken for Pregnant: When Kaho gets sick due to PTS Meg Brown assumes she's pregnant with Natsu's child. Natsu is a bit taken aback, given that he'd never had sex with her.
Mob War: A plot point.
Murder, Inc.: Mother & Children.
Mysterious Past: Yuki.
Nakama: Yuki, Natsu and Kaho.
Only One Name: Yuki and Female Yuki. Turns out Yuki unconsciously took his name from Female Yuki, so his real name is unknown.
Only Sane Man: Natsu is pretty often this.
Rule of Cool
Scars Are Forever: Natsu has scars all over his body.
Shirtless Scene: Yuki, pretty often. Natsu and Higa get some scenes as well.
Shout-Out: Yuki and Natsu are based on Harry and Ranmaru, members of the classic Japanese rock band The Street Sliders. (Vocalist and lead guitarist, respectively.)
- The cover of volume 5 riffs on the poster of Enter the Dragon.
- And keepin' the summer alive...
Shower of Angst: Yuki, after Natsu is shot and captured.
Storming the Castle: Yuki and Higa when they try to get Natsu back.
Strange Girl: Chigira. And Kaho is pretty strange herself.
Stripperific: Female Yuki's combat outfits usually combine this with Combat Stilettos and Vapor Wear.
Team Pet: Suji-Q, the leguan.
Triang Relations: Type 8, sort of, in the trio. Natsu and Kaho clearly have feelings for each other, and everyone assumes they're an item; but there's also open attraction and flirting between Yuki and Kaho. Natsu is also very attached to Yuki to the point of being jealous of Higa, and Yuki regards both Natsu and Kaho as belonging to him.
Unlucky Childhood Friend: Chiaki is implied to be this to Kaho. They get on pretty well, regardless.
Unusual Eyebrows: For some reason Natsu has no eyebrows (he probably shaves them because from time to time he displays some).
Yakuza: A lot of them, including Higa and his gang. Yuki used to be one, too, but quit to be with Natsu.
You Need to Get Laid: Higa's reaction to Natsu's hotheaded behavior. "How about getting some of that energy out of your system? With Kaho."