If you want to kidnap girls, do this:
Go to class (press T to find your class) and study biology, study it until you reached rank 1 biology
after that go get the syringe and tranquilizer in the nurse's office
get a girl to follow you the the north-west storage room
bang that girl with dat syringe and put her body in the box
end the day
if you get home, go to the basement
Torture her, when her sanity reaches 0, bring her to school.
You officially summoned a mind-slave