Rika Saginuma's a disenchanted teen - dumped by her boyfriend, off the track team due to an injury - who finds her way into a chat room peopled by 4 similarly disgruntled souls. They meet up at school, exhange contact info, and agree to stay in touch ... The 4 kids are all beset by problems that seem to overwhelm them ... yet are united by a common fascination: blowing up their school on X-Day ...

Rika Saginuma
The story's main character and a high school student. She is referred to in the story as Rika and by her online user name, 11. Rika was a record-setting track star who finds herself re-evaluating her life after a sports injury.

Nanaka Shimada
A fellow student who is referred to throughout the story by her online user name, Polaris.

Yumihiko Tsukumura
A male student at Rika's school who is younger than she. He is referred to throughout the story by his user name, Mr. Money.

Reiichi Katano
An 'unsocial' biology teacher at Rika's school. He's referred to throughout the story as Mr. Katano and Jangalian, his user name. He is being romantically pursued by another teacher, Ms. Kunimoto, who is also the school chancellor's daughter, but he has no interest in her and tries to avoid her.

Ryo
Rika's ex-boyfriend. He is now dating another student named Kako, who is on the school's track team and breaking Rika's records.

Ms. Togawa
A teacher at Rika's school who always asks Rika when she's going to return to the school's track team.

Setona Mizushiro
Setona Mizushiro is also the author of the shounen-ai manga series, Mr. Mermaid. She made her manga debut in 1993 with a series called Fuyu ga, owarou toshiteita.

She was born in Kanagawa prefecture, Japan, and her blood type is A.