No Bra

Even knowing that Yuki is really a boy doesn't stop "straight" guys from falling for him.

No Bra is a Japanese teenage romance manga written and illustrated by Kenjiro Kawatsu that has been serialized in Shōnen Champion Comics since 2002.

It tells the story of Masato Katoka, a somewhat dimwitted high school student, whose childhood friend Yuki Nomura moves in with him one day. Because of Yuki's cute face, girlish clothing, and apparently feminine features, Masato is extremely happy with his new life -- until Yuki's mother calls Masato, and tells him that Yuki is a boy. The story revolves around Masato's relationship with Yuki and his slowly disintegrating reluctance to develop romantic feelings for him.

Not to be confused with Vapor Wear. Contrast Prunus Girl, and The Secret Devil-chan, which explore similar themes.

Tropes used in No Bra include:

Attractive Bent Gender: Yuki is so feminine that Masato occasionally has to remind himself that Yuki is not a girl. Something many readers can sympathize with.
- Not surprising, considering those panty shots. Apparently Yuki is an expert at "tucking," and is not very well endowed.
Betty and Veronica: Gorgeous housewife-in-the-making Yuki is Betty, while stunning athletic Kaoru is Veronica.
Big Guy: Hideki, Masato's best friend, who towers over the rest of the cast and has a major crush on Yuki, but is also a firm supporter of Yuki's love for Masato.
- Hideki's also pretty unique in the Big Guy department for not just clearly being fat, and not just clearly having consequences of such (sweating, overeating, etc.), but the fact that everyone still treats him like a normal person.
Bishie Sparkle
Bishonen
Black Comedy Rape: First Mizuki does this in her first appearance to get information out of Masato, then Mizutani does it to get to stay in Masato's apartment. Both despite his protests to stop.
Blatant Lies: Masato tries to cover up his cohabitation with Miss Mizutani from Yuki's cousin with a couple of these. She doesn't really believe him, but the only reason she cares at all is because it makes him squirm.
Bottle Fairy: Masato and Yuki's teacher, Miss Mizutani (who moves in with them to keep from having to pay rent), spends most of her time when not working drinking.
Cassandra Truth: For the first couple of chapters, Masato tries to inform people that Yuki is male.
Chekhov's Gun: "Maa-kun's" dislike of frogs.
Double Standard Rape (Female on Male): See Black Comedy Rape.
Dropped a Bridget On Him: Masato is very surprised to find out Yuki is actually a boy.
Ecchi: Chapter 12. And again, with the same lady, in chapter 22.
Even the Guys Want Him / Even the Girls Want Her: Yuki towards the end. It Makes Sense in Context.
Gayngst: Masato is put through this mercilessly once he starts developing feelings for Yuki.
Hartman Hips: well, do YOU know any teenage boys that shape?
Hot for Student: Well, not quite played straight in that Mizutani-sensei has started throwing herself at Masato not because she has feelings for him or actually wants him, but because she doesn't want to get kicked out of the apartment (see Pretty Freeloaders), and knows Masato has trouble saying no to a girl if she's getting physical with him.
I Didn't Mean to Turn You On: All. The. Bloody. Time.
Informed Attribute: Yuki's male status.
I Want My Beloved to Be Happy: Both Yuki and Hideki have this attitude towards their respective love's Love Triangle partner.
Kavorka Man: Why does everyone and their grandma want to jump in bed with Masato? He's not that hot!
- Oozura just happens to like him, Yuki sees him as Maa-kun and Mizutani wants a place to stay.
- The fans know he's a lying pervert through reader omniscience, but Yuki and Oozura don't know that. Which is why there are so many rooting for Masato to fall flat on his face.
Love Triangle: Several of them, but most prominently a Type 4 with Masato at "B", Yuki at "A" and Kaoru at "C". It later shifts into a Type 7, much angsting by Masato (now in "A") and Yuki (now in "B") follows.
- It's shifted again into a bizarre form of Type 8, where the relation is THERE but Yuki and Kaoru are unaware of it.
Mistaken Identity: Masato and "Maa-kun" are not the same person. The real Maa-kun is Masato Kaoru, a.k.a Oozura Kaoru, who is not only a girl in reality, but Masato's girlfriend.
- Not to mention how Masato lands Oozura as a girlfriend. Oozura apparently fell for him because "he" saved her from a molester on a train. Well, she thinks it was him because of the Hawaiian shirt her savior wore and Masato likes constantly wearing Hawaiian shirts. Masato, however, is pretty sure he never did anything that heroic and thinks that the guy Oozura saw was probably a plainclothes police officer.
Moment Killer: Mizutani is good at this.
- It happens to her and Masato as well.
- As seen in chapter 22, this applies to her in both the giving and receiving end of the trope!
Panty Shot: Many of them of Yuki's behind.
- It helps that the panty shots never show any indication that Yuki is smuggling any budgies down there despite the fact that Yuki is supposed to be a boy.
Pair the Spares: Minor one: Hidepon ends up dating Mizuki
Pretty Freeloaders: Mizutani once she moves in with Masato and Yuki, under the pretense of safeguarding Yuki's "virtue".
Raging Stiffie: Represented by a mini-shark. And it talks.
Stupid Sexy Flanders: Yuki not only makes the main character question his sexuality, but most of the male readers as well. The manga seems hellbent on making people realize that their sexual orientation isn't as black and white as they like to think it is.
Transgender: Yuki seems to be, for all intents and purposes and Fan Wank about him "really" being a transwoman. When she's forced to dress as a boy late in the series or risk being kicked out of school the other girls even say that she has the heart of a girl despite having a male body.
Their First Time: Oozura offers herself to Masato this way. Masato runs away, but later on gets (and takes) a second chance.
Third Option Love Interest: Mizuki, that giant skank.
Vapor Wear: Mizuki.
Wholesome Crossdresser: Yuki practically embodies this trope.
Yamato Nadeshiko: Oh, my, Yuki!
Zettai Ryouiki: Yuki has these in the first chapter and subsequent scenes.