Miroku Shochikubai is the son of a police commissioner (father) and a traveller (mother). A very good fighter with lots of connections.
His main interest is his motorcycle though.
Seishiro Kikumasamune is the rich son of a large hospital's head doctor. A good fighter with smart moves, on the same level as Miroku.
Jean-Marie "Granmarie" Bido is the son of a Swedish ambassador. He's also a playboy, dating many girls at once: can't see himself
going steady because he thinks the world can't handle it.

Yuri Kenbishi is the rich daughter of a world-renowned president of the Kenbishi Business. She loves to indulge on eating.
She's also a good fighter, but can never beat Seishiro.
Noriko Hakushika's parents are a famous japanese painter (father) and a traditional tea ceremony master (mother).
Her only hate is men and can get very violent when they touch her.
Karen Kizakura lives with her mother, a rich jewel dealer. Her dream is to marry into a rich family using style and her attractive body.

Together, they formed the Yukan Club solving mysteries to pass time.

• 1986 Kodansha Manga Award winner for Shojo