Seitokai no Ichizon

Seitokai no Ichizon summary:

The student council members of a certain high school are chosen by an extremely unique method: They are chosen based on their popularity with the other students of the school. This unique balloting system has resulted in a student council full of pretty girls, with the third-year Sakurano Kurimu as the student council president.
However, one member of the student council did not get in based on popular vote, but by taking advantage of a loophole which specifies that the student who tops the school in the year-end examinations may choose to join the student council. That student is Sugisaki Ken, a guy obsessed with eroge whose goal is to make the student council into his own personal harem!