Shinjiro is Akihiko Sanada's childhood friend and was an orphan at the same orphanage. He is a senior in Gekkoukan High School, although he doesn't attend class often. Shinjiro was one of the original Persona users who made up SEES, alongside Akihiko and Mitsuru Kirijo. Unfortunately, during one fateful mission two years ago in 2007, his Persona went out of control and accidentally killed an innocent bystander: Ken Amada's mother. Shinjiro forced himself away from the group after the incident. He began skipping school and living as an outcast. He also started doing shady deals with Strega in order to get suppressants that could help control his Persona.
Shinjiro and Akihiko have stayed in touch over the years, but Shinjiro refuses Akihiko's invitations to rejoin SEES until he learns that Ken has decided to join their group. He is fully aware of Ken's vendetta and is ready to take responsibility for his actions. Though he puts on a brave front, the guilt of having killed an innocent woman ate away at him.
