There's at least 1 flashback where she remembers the first time they met (chapter 9, page 12, if my memory serves me right some later chapter should also have a flashback) with Tatsu bleeding from multiple wounds and looking like he was defeated. Maybe that's actually the result of Miki accidentally doing something to him and he fell in love with her because she's the first person ever to defeat him.I swear she seems more dangerous then tastsu