The Seventh Neck (七の首, Nana no kubi), he is the only Orochi who was able to resist becoming completely evil. Sōma is the lone protector of Himeko and Chikane for most of the series and later plays a part in bringing the Orochi down. He has a very high social standing at their school, comparable to Chikane's, and most of their fellow students believe they are dating, though in truth they rarely interact until the Orochi events.

Spoiler

Like Chikane, he is in love with Himeko and is incredibly protective of her, fighting to keep her safe until he is overwhelmed by the Orochi curse and put out of action, though he is later rescued by his brother Tsubasa.