Sun Chan is the star of the Solar System! She has helped provide light to each of the planet chans and moon chans for the past 4 and a half billion years, pretty much uninterrupted. She has seen stars pass by the Solar System, in which she has seen about 20 in her life time. Sun Chan is the life long caretaker of everything in the Solar System, and as such she has a motherly and treats everyone with equal amounts of love and care, though she finds bigger planets more impressive!