Bought by me
https://www.dlsite.com/maniax/work/=/product_id/RJ402321.html

Synopsis:
*Warning: Disgusting content*

Hiiro has been dating her childhood friend Hinata since elementary school.
He has cherished her for 10 years.
Today they kissed for the first time.

That night, Hiiro witnesses the body of her classmate Aki being dumped.

Aki is a psychopath who kills people in order to see the faces of people distorted by pain.
Aki says one condition for keeping Hiiro, a witness, alive:

"Let me do it."

Base +2

I feel sorry for Hinata; Aki didn't let her go after just that, he wants more as he tells her to meet him in the restroom near the gymnasium during lunch break. Hiiro felt something was wrong so he asked if Hinata was alright but when she was about to tell him something, she stops midway and says everything is alright. A very open ending.

Gotta day this offers a stronger case of forcing a woman to go along their twisted whims than many other works out there, this is literally life threatening.

Base +12