Anime and Manga and the other things you mentioned are hugely popular outside of Christian circles and have been for the past 20 years, in the US.
And I know I've seen plenty of Christians come through this site with your interests, but rarely do they stick around if they can't find the niche they're looking for.
And I said nothing about not being yourself. I merely suggested expanding yourself, while still being yourself. If these are your tastes and interests then it's fine to express them and want to find others with similar tastes. But when you have less popular interests sometimes you have to decide between sticking to them, and only them, staunchly, and being alone vs learning to expand and find people.
When I met my gf, according to how she'd been taught, she should have nothing to do with me. But she gave me a chance and learned I was much different than what she'd been told I would be.
Since then we've both learned and grown and expanded ourselves, thanks to the other. Neither of us gave up being ourselves.
And who knows, perhaps making a friend without your tastes might lead to them becoming interested themselves, not that that should be a goal, but it's possible.