Escalation'95 Onee-sama tte Yonde Ii Desu ka?

Escalation '95 doesn't have a particularly elaborate story: the protagonist is a female student named Naomi, who attends the Catholic St. Azarea high school. At the beginning of the year, new students enter the school, and Naomi's task is to show them around and help them - which she does in a very particular fashion...

[From Mobygames]