Age:17 (Amagami SS), 18 (Amagami SS Plus)
Class: 2-B
Club: Tea Club
Height: 164 cm
Weight: 57 kg
Birthday: April 12
Blood type: A

She is Junichi's childhood friend who, despite having a big appetite, avidly reads the dieting books in their school library. She is a member of the Tea-Making Society.

Riihoko's arc is the 5th in the Anime.