相楽 深行

Miyuki Sagara is Yukimasa Sagara's son and Izumiko Suzuhara's childhood friend. He enrolls at Hōjō High School in Tokyo with her when she expresses a desire to be in the city. Miyuki discovers that he is a yamabushi, a warrior tasked with protecting Izumiko who is a "yorishiro".

(Source: Red Data Girl Wikia)