It seems like he really loves her.

Comic Synopsis

Mitsuba Hanatani, a plain college student, confesses her love to Makoto Shinomori, a senior student she has had a crush on for many years, but her confession is rejected.
On the contrary, he introduces him to Louis, saying, "My younger brother is gay too."
"You're too much of a stretch for a straight guy like me," he said. "I'll teach you."
He ends up receiving instruction in sex between men...
A love triangle between brothers and a story of unrequited love