https://www.dmm.co.jp/en/dc/doujin/-/detail/=/cid=d_128231/

DMM Summary:
The protagonist, Taro Yakake, is an ordinary salaryman living a dull life.
He has a job in the legal field, and his work is going well, but he doesn't have any special characteristics, and his life is not very exciting.
One day, Yuki Ayase, a woman who lives next door to him in his apartment, asks him for advice.
Yuki Ayase was a woman that Yakake had been interested in for a long time.
She is neat, soft-spoken, and good-looking, and Yakake wants to get her, but he has been unable to do so, until he finally gets his chance.

A sudden consultation, in his room. The other party is the woman he has been in love with for a long time.
A black desire begins to well up in his heart.