As someone who read lots of GB stuff this one is honestly predictable to satisfy male readers. (Romcom, Isekai, Genderswap) like bruh.
I am just going to nope the shit out until it somehow ended but, pretty sure I can guarantee they'll get together by the end just from seeing chapter 1 unless the author can prove me the otherwise.
Easy to see where this is going for Tachibana. Will eventually see that his new body has alot more going for it than his old one and there fore will loose interest in turning back to his old self.