Quiche comes off as a playful and cheerful person, but this aspect of his personality is often hidden by his sadistic tendencies and lack of respect for personal space. He enjoys seeing humans in any sort of pain, is amused by playing with his victims, and has no respect for youre personal space, forcing his affections on you multiple times.
He is also rather jealousy-prone, trying several times to murder youre crush so that you're heart will be his. He doesn't seem to trust people very well.