No Bra/YMMV

• Epileptic Trees: As seen below, the idea that Yuki might actually really be a female, and his mother was just mistaken or having a joke at Masato's expense or so on... basically, a lot of explanations for Yuki possibly actually being a girl. This is despite the fact that the manga has gone so far as to have Masato see Yuki naked and sitting in his lap at one point, and he still thinks Yuki's a guy.
• Fan Wank: Some of the theories about Yuki "really" being biologically female can reach these levels. The manga was even encouraging some of the early fanwank, since even Masato wasn't sure Yuki was really biologically a male, and a couple of times tried to catch Yuki changing to verify it (although he either chickened out or was thwarted).
• The Scrappy - Masato, due to the way he treats Yuki and Kaoru.
  • At the very least, he's finally manning up and telling the truth, even if he did take his sweet time about doing so. Your Mileage May Vary on whether that's enough to rescue him or whether it's too little too late.