It would actually be pretty subversive if Tastsumy truly is just straight as nails and there's nothing that Amachi can feasibly do to achieve his happy ending, it'd be a pretty logical explanation as to why he seemingly hasn't noticed Amachi's very evident feelings, he just chooses to ignore them cause it makes him uncomfortable to be loved by a dude.
Tho more likely next couple of chapters he realizes that he does love him they decide to go to Tokyo and then the manga ends, we will be lucky if there's a kiss at the end.