Shiba, also called Shiva, is the son of Shu, a prominent resistance fighter. He fights alongside his father against Souther's oppressive regime, which kidnaps and enslaves innocent children. To protect others and advance the resistance's goals, Shiba executes a critical diversionary mission by deliberately luring Souther's troops into a canyon pre-planted with dynamite. With the pursuing forces inside, he detonates the explosives, sacrificing his life to bury both himself and the enemy soldiers under an avalanche. This sacrifice creates a crucial tactical opportunity for Kenshiro to confront Souther. In other media, specifically Rei Gaiden, Shu references Shiba sharing a younger brother-like relationship with Airi.