Attacks: Fallen Blossoms, Swallow's Return, EX Cherry Blossom
This can be an easy fight. Don't attack her until you see her EX gauge is full (and she goes into her stance), otherwise she will counter attack you after each time you attack her. Whens she's in this stance is the only time you should attack, that way she can't counter (make sure you have enough of the potions that heal your HP and your EP, that way when she uses her cherry blossom attack you can heal as it leaves you with 1 health left). After a couple rounds of this she will be beaten and you will have another achievement.