Am I delusional or is there actually a chance here?

Am I delusional or is there actually a chance here?

i am a 26 M, from Japan , I am pursing my Master's degree and working part-time. There's a girl (26 F) I really like, and honestly, I can see myself marrying her one day.

I am active, do lots of exercises and in a band as guitarist

The confusing part is her behavior. She jokingly calls me "brother" and says she's older than me even though we're the same age. Whenever I hint that I like her or joke about marriage, she says things like "never, not you," "never in a million years would I marry you. "you're like a brother to me," and even "Eww I have no feelings for you.

Normally I'd take that as a clear rejection, but her actions make me question everything. She replies to my messages almost instantly, never turns down my invitations to eat or hang out, and constantly makes dirty jokes and double-meaning jokes with me. She tells me I'm a really good person and husband material. She has said that even when she doesn't feel like talking to anyone, she'd never ignore me. recently she move to other part of city but she gave her address but as of now we both are really busy due to work and life.

She also sends me screenshots whenever guys flirt with her and says things like "this guy is hitting on me" or "I'm blocking him." She doesn't really entertain other guys and is always pushing me to do better in my studies and life. She jokes that she hates men except for me and often calls me things like "my gay boy."

She recently went through a breakup, so part of me wonders if she's afraid of opening up again. At the same time, maybe I'm just seeing what I want to see.

The biggest issue is that I've had chances with other women, but I've turned them down because I only want her. some how i feel like this is a talking stage and i have to be loyal to her no matter what.

From an outside perspective, does this sound like a girl who secretly likes me but is scared after a breakup, or does it sound like she genuinely sees me as a brother and close friend? Am I wasting my time hoping for something more, or is there actually a chance here?

I'd appreciate honest opinions, even if they're brutal.

( i am not confident with my English so used CHATGPT to fix )