Well this was a nice ride it took me on
I enjoyed the manga overall, though I was worried a bit with how yandere-ish she was
But all's well that end's well

Betcha Akira's friend who turned out to be Koharu and Akira's daughter's sensei is bitter not because of the whole like mother light daughter thing, but because she still hasn't found love and is still a bitter virgin at her age.