So while I've been in Japan; I've actually had two jobs. The first was an after school teacher, where I taught the same group of kids every day for 1.5-3 hours a day. The one I'm currently doing is an Eikaiwa style job, which is where I teach different kids every day, for only an hour. So I knew the kids in my previous job a lot better, as I saw them everyday. That being said, both jobs were mainly with kindergarten kids.
I have some kids who love Kamen Rider, One of them has brought a magazine about Kamen Rider in before (at least I think it was fully focused on Kamen Rider).
I actually have two kids in my current job that are obsessed over Smash Brothers! One of them used to come in every week and asked if I unlocked one of the unlockable characters or stages. Both kids only play the 3DS version, and I've played both of them.
Yokai Watch is very popular! I see a lot of watches, medallions and games. It's dying down a bit, but I'm sure it'll pick up again when the new game releases.
It wasn't a mean look, it was more of "oh god, someones talking to me. What do I do?" look.