One of the youngest in Hinamizawa’s school, Rika is the current presiding miko over the Furude Shrine, which is maintained by her family.

She is a very quiet and reserved girl who can be found comforting anyone who seems to need it. She seems happy doing so.

Due to her family’s high status in the village, Rika is is often referred to as ’Rika-chama’ by her fellow villagers in Hinamizawa, an endearing title indicating both her youth and family position.

Formerly a detective under the Primary Investigation Unit in Okinomiya.

Oishi works together with his junior police investigator, Akasaka Mamoru, to investigate a kidnapping case in Hinamizawa.