I came across this after reading other work by the author, then realised it's the same teacher that then goes on to darker stuff; after putting two and two together I was straining for the developments here.
I don't usually read BL, but this has that old seventies manga reminiscence; when you actually want to read dramatic manga you don't pick up the fruity nowadays stuff... But this author reminds me of other good contemporary, Asumiko Nakamura.