The title basically already describes the entire story. It is exactly that, he wakes up, suddenly a high schooler again, and pretty much the first thing he does is to confess to his teacher, who for whatever reason accepts. Now, if you look at the art style of the female lead, it's obviously going to be somewhat ecchi and fanservice, however not over the top in my opinion.
The story in its grand scheme doesn't make too much sense, but the art looks nice, the character interactions are cute, and sometimes funny enough to cause some chuckles too.
