bully her
When I say that, I simply mean ridicule her about it until they stop being cringe
Get a group of like 2 other people in case this shithead decides to snitch; so you have people to back you up, and it's 3 people's word against 1.
(I'm also going to assume the person's female because I fuсking hate using gender-neutral pronouns)
Say something along the lines of (and this is based solely on what you tell me) this:
Listen friend, the way you celebrate anime character's birthdays is cringe, as well as that song. Everybody thinks that. You can get more friends by not singing like that and not celebrating fictional character's birthdays as well as dressing normally. [because I presume that they likely also dress oddly based on the way that you describe this person.] A t-shirt and khakis are some clothes that won't get you judged but also allow you to express yourself with logos on the t-shirt.
Of course I presume they won't listen to something like that, so just wing it. Remember to emphasize the following:
-you're telling her this for her own good; people will take her more seriously if she doesn't act oddly.
-most, if not all people find it cringe
This is of course not counting the fact that this person may have some sort of neurodevelopmental disorder; If this person does, don't do anything. There's nothing you can do against this person.
Caption this Meme
