Great ending.
A fine mess, eh? Well, yeah. I mean, they have blackmail material and I don't see them stopping this relationship with you for awhile.
Not that it's really that bad of a thing. Really, he should just embrace it. Not like he has much other choice.
Eisuke! \o/ to be honest when i saw the tags and the first page i was sure it would involve rape or something like that. It was a nice surprise. I could call it somehow a vanilla + harem cause i don't see the sensei choosing one of them and they will blackmail the shit out of him hahaha.