I think it is probably best to tell him, if I were in his position, I think I would rather know what it actually says

You should tell him op. It will only cause further embarrassment if you dont. Plus you should go tell him yourself in private, that way if he knows you can actually speak Japanese he won't think it's just some student trying to make fun of him :)

You HAVE to tell him!

lmfao!

I'd tell him in private.

f your teachers life lol. I'd tell him

If you tell him it won't be the end of the world. At least it is a painting and not a tattoo. If you want extra brownie points you could even show him what his name actually would look like in Japanese. If you can like write in Japanese too :)

At least it wasn't a tattoo OP. So many people walk around with Asian signs tattooed on them that reeads completely differently to how people had intended it. My friends walking about with a tattoo that says "old woman" instead of "mother" as she thought. Authenticate it first guys!

at least it wasn't a tattoo like what some people get

funny :p