Is watching anime illegal?

Answer 1

No it's no. Why else would it be on TV? XD

Or are you talking about the controversial anime like animated p**n, lolita complex, shotaru complex related anime? I know you can watch hentai or any p**n IF you're above 18.

As for lolita and shotaru I'm not sure but there's a lot of debate about the hentai versions of loli/shota being related to virtual child p**n. Virtual child p**n (in general) is still being debated.