How to impress an anime lover girl?

When she mentions anime, the show itself is less important than the way she talks about it. Look at whether she names a specific character, a scene, an arc, or a studio, or whether she just says "I love anime." A specific reference means she has opinions she wants to share. A vague one means she is mostly signalling identity. Both are fine, but they call for different replies. With the specific version, you can ask about the detail she chose. With the vague version, ask what got her into it, because the answer usually tells you a story about her.

Also notice whether she is inviting you in or testing you. A line like "yes I will talk about it for an hour" is a dare and a warning at once. She is saying she expects to be teased or tuned out, and she wants to see whether you'll stay with her on it. That means the reply should feel like you're taking the bait willingly, not hedging.

The useful replies to this kind of message share a shape. They pick one concrete element from what she wrote and respond to it with a real take or a real question. Something that proves you heard her specifically. A good reply might agree or disagree with a choice she made, name a character you find interesting and why, or ask how a show landed for her at a particular point in her life. Each of these moves the conversation forward because it gives her something to answer that is more than a list.

Leave out anything that is about showing off. Don't list every series you've watched, don't rank her favourites against yours, and don't announce that you are also a fan unless it's true and relevant. The reply should make her feel the conversation is about her taste, not your résumé.

Once she's talking, let the thread run for a few exchanges before you change the subject. Anime conversations often go deep quickly and she may be happy to spend an evening on one show. Don't rush to pivot to plans or meeting up while she's still enthusiastic. If she sends a long message, reply to the most interesting part, not the whole thing.

If the replies get shorter or she stops asking anything back, that's the signal to lighten up, not to push harder. Send one light message later that doesn't need an answer, like a reference to something you talked about, and see whether she picks it up. If she doesn't, let it go and don't send a follow-up the same day.