Answer:
Nothing.
Explanation:
It's a fictional character that has no consciousness. So what if people "like" the character? It's not like the character likes anyone back, or can suddenly become aware of your emotions.
The fact that you see your friend as a potential threat for holding a similar interest in the fictional character holds no basis for logic.
The truth is, if you for some reason are upset that someone you know likes the same fictional character you like, then you are being petty.
Well, it is customary not to say anything at all, but they mostly say, “Odaiji-ni” as referring to when someone has a cold.
Write in English because we don’t understand what you mean
