Responses
I think realising your sexuality isn't something that is just "oh, okay". It is more "I thought I was this, but now there is this, I see". So a bit of confusion in the beginning is normal. Especially if they had a sexual identity - or thought they did - before.
True, although for me it was more like "wow he's really attractive" Three months later I found out that being gay existed, and it was the minority (this was age 13).
Get rid of that "but he's a guy/boy" stuff since gay is accepted by most people other than parents+children who are completely racist, homophobic, religious, etc. This manga only had it for a moment which is better than some mangas that do it for half their entire story