"My little sister turned me on." Ooh baby. This is an amazing start, lol. The art is gorgeous as well, I like the thick lines and stuff.
I read somewhere the suggestion that the Teacher's kiss was forced, that makes a lot of sense for the logic behind Aihara's actions.
The writing for this one seems kind of crazy but I think it will at least definitely be very fun to read. I hope the characters can realize their feelings quickly so that we don't have to suffer through more forced het, though. Aside from that this is quite an impressive manga, I especially also like the unexpected friend character, "Harumin", lol.