Kochou Shinobu is in love with him.
Tomioka Giyuu is in love with her.
It's pretty simple.
Except it isn't. Not with the barrier built between them by society and law.
Shinobu knew him for years now. It started with her sister studying in the same course as him, and goes on with him being her teacher. Tomioka is kinda odd and antisocial, but that just makes him more endearing. He is handsome and good at heart, so it's no wonder she's been crushing on him since puberty.
If only Tomioka wouldn't be so difficult about this.