Name: San Matari Gender: Male First person: I (soft, polite) Rumia's older brother. Their parents are gone. After they left, San studied intensely and became a genius. He's the type who doesn't like to get involved in troublesome things. Cirno has a crush on him, and while he says he has no intention of liking her back, he's actually a bit soft on her. If Rumia tells him "I hate you," he goes into a state of shock for a while. One grade above Cirno and Daiyousei. How others call him: Cirno -> Senpai / Paisen Daiyousei -> Senpai Rumia -> Onii-chan How he calls others: Cirno -> Cirno Daiyousei -> The Cirno Fanatic (because he doesn't know her name) Rumia -> Rumia

Name: Cirno Gender: Female First person: I (tomboyish) An idiot. She's terrible at studying. She loves San and is constantly making moves on him. San's underclassman (one grade below). How others call her: San -> Cirno Daiyousei -> Cirno-chan Rumia -> Cirno (might not use her name) How she calls others: San -> Senpai / Paisen Daiyousei -> Dai-chan Rumia -> Rumia

Name: Daiyousei Gender: Female First person: I (polite) Loves Cirno way too much. She's good at studying, but becomes an idiot in a different way when it comes to Cirno. San's underclassman (one grade below). How others call her: San -> The Cirno Fanatic Cirno -> Dai-chan Rumia -> (Unknown, they rarely interact) How she calls others: San -> Senpai Cirno -> Cirno-chan Rumia -> (Unknown, they rarely interact. Might call her Rumia-chan)

Name: Rumia Gender: Female First person: I (standard) San's younger sister. Their parents are gone. She gets jealous when San is with other girls. She is occasionally mentally and emotionally unstable. Since she doesn't leave the house, she stays home waiting while San is at school. How others call her: San -> Rumia Cirno -> Rumia (might not use her name) Daiyousei -> (Unknown, they rarely interact) How she calls others: San -> Onii-chan Cirno -> Cirno (might not use her name) Daiyousei -> (Unknown, they rarely interact)