Ayane has a thing for clan leaders. For some unknown reason she was Murai's servant in NG1, her hanging with Joe Hayabusa at his bedside behind closed doors in NGS2, and her unhealthy obsession with Hayate who happens to be her half brother in DOA.
Ryu may have a thing for blondes but Ayane is all about the alpha males.
Nah man...she was ready to kill herself when she thought Hayate hated her. She's one heartbreak away from fatal attraction, that one is...she's either just mental unstable, or has something more specific wrong with her (like bipolar disorder). A lot of it comes from childhood trauma.
...now that I think about it, maybe she likes all these clan leaders because they can give her some counseling?
"We've made some real breakthroughs today, Ayane...but your 60 minutes are up."
It's fine, Ayane. I'm not exactly normal either, and I still like you.
"It means that Sir Issac Newton is the deadliest son of a $%#^ in space."