Upperclassman is the only gay guy, though. I'm assuming you mean Sun Jing's and Mophead's friend, who Upperclassman likes, but nothing Tan Jiu has shown us so far indicates that he reciprocates UC's feelings. In fact, most of his reactions so far are of crippling discomfort and panic.
You’re right—I was reading his reaction in that “you’re cute, girls would like you, also guys” scene as an “Oh shit, my secret feelings have been revealed” panic. Then that random guy kissed him in the restaurant, which is certainly an unfortunate coincidence if not a gaydar reading.
In other words, if he's gay, he's at least closeted, in denial, and maybe even self-hating. Is it possible that the story is about him becoming comfortable with himself and dating UC? Maybe, but there's no real indications of it.
People have been making the point that even the narrative sections of the series were pretty diffuse and indirect as far as which threads were important for future development. Along with the elements we’ve mentioned, there was the budding “friendship” with the rival basketball guys, as well as the academic rivalry between Mophead and Tattletale (Mophead saving Tattletale from falling off the chair is for me of the more visually memorable scenes in the series).
It’s pretty clear that Tanjiu was gearing up to continue the series as it had been going by focusing on SJ & QT while throwing Mo into the mix, with Mophead and Eager Girl as a subplot, when something happened and everything swerved (in terms of story format). But there’s no indication that the story was going to become more sexually explicit—and it’s always been about a lesbian relationship.
It’s almost like Dynasty needs a new term. This series and, say, A Room for Two are about girls in a loving relationship that’s as “text” as text can be, but neither may ever (for various reasons) supply the kind of evidence the yuri-skeptics are looking for.
(My own preferred term is “yuri.”)
