This is what I did: At some time, i don't remember if was morning or afternoon i went to the library and rent a book (I don't know if it's necesary. It's called The Gift of Love)
Then I get naked on the locker in the 2 floor classroom, and I hide to trigger evening time. Then I went to the third floor, and near the art club there would be an envelope. This is the invitation for the party.
The next day repeat with the locker, but there will be a circle on a diferent spot. Wear the gift suit and hide to pass time. On evening go to the chorus club and enjoy