[Sunred]

Quote:

Originally Posted by Zolda

Hanto tells Shouma his sob story about his mom being kidnapped by a mysterious, elusive Wolf(?) Granute 18 years ago @ 08:49. He shows Shouma the photo of his kid self with his mom. Aaannnddd... Shouma is suddenly experiencing a painful flashback of an unknown memory.

The headache does seem convincing of it likely being the case. At the same time, one speculation I have thought up for now is someone else was fitted with it, a test subject before Shouma, and the Gavv belt happens to retain the memories of that test subject.