Holmes! Decchiage Meitantei

Yuuki Kanou is a student who calls himself a descendant of Sherlock Holmes. He tries to solve mysteries that happen at school together with his partner Yuki Matsumoto who he calls Watson.
His method is to use deduction to prove guilt of a girl and then force that girl to making love. There are 4 cases in total in the main part.

[From vndbreview]