I don't know what I've done wrong, but in my game I couldn't continue the science club event passed the science 3 after I found the letter that point me to check the locker in empty classroom. I've check all the room in the school building minus Girl's Gym Locker room because it's locked, nothing except "barging in" into the science room which lead me to bad ending. Is it bug? or am I missing something? Any pointer would be mostly appreciated.