Tokai Mima is the main character, a lost young girl. She's unmotivated to work in school, and feels constantly in competition with her pretty older sister in all areas of her life - from school to men to growing up. Mima's sometimes impulsive and often defiant, but mostly wanders around feeling as if she has no guide through life and no will to find one. Even though she likes Maejima-sensei and the attention that he pays to her, it doesn't quite seem enough...
	Tokai Sawako is Mima's blond older sister in the tenth grade; Mima calls her "San-chan," and thinks that she's pretty, smart, and mature. Sawako can cook, too, and has excellent manners. She's also graceful; Maejima says that she's like a bird's feather. A while back, Mima's crush fell for Sawako, making Mima bitterly jealous of her pretty sister who seemed to have everything. But Sawako has a hidden sadness inside her as well.
	Maejima is an intense young man who teaches English at Mima's school. Initially concerned about Mima's low grades, he offers to tutor her at home... and is entranced by Sawako. He's direct and quick to react to things. Having the drive that Mima lacks, he works very hard. Like a small child with great dreams, he wants to enter NASA as a pilot, and is assiduously learning English. He also likes physics.