Hiro had almost forgotten about the Dark Hour. Sure, he'd logged it away when Minato had told him about it, but only as a curious kind of "oh man I wish I got an extra hour in the day to sleep" kind of thing. When Ken puts it that way ... Hiro pales a little, trying to picture it. Especially considering that Ken's mother was killed by a Persona ... He has enough trouble facing Callaghan as it is, much less with an hour every day as a living reminder.

"So you could protect people. Who couldn't protect themselves." Not a bad plan.