Chinen was the Head of Housen Academy during the time of the Umehoshi Brothers. The Twins had known Ryuutarou througout middle school. During his 2nd year he was jumped by a fellow Housen Student Nikaidou Takuya.
Before the jumping, Housen was in a power struggle between Chinen and Nikaidou.
It was said that Chinen was an Idiot but he at the same time sensible.