I introduced Touhou to one of my friends with fan musics. She happens to like songs with depressing lyrics and the first Touhou fan song I sang was Bad Apple!! (She was stucked with Bad Apple and I can't get her to listen to other Touhou songs for a while so I basically left most of the making her get into Touhou thing to Youtube Recommendations for a while lol) I make some Touhou jokes here and there whenever I see fit (such as me telling her that she's being Flandre when she breaks my correction tape. That always happens when she uses a correction tape) or tell her about some scenes from manga. As she doesn't play computer games, I can't introduce her by games, though.
And now I'm passively forcing her to read Dipp lol.
(Alright, this is not useful but whatever. I'm gonna leave the message here.)