Manga where the female protagonist has amnesia I came across this manga by accident and I can't remember what it was called.

The main character is a teenage girl, who lost her memories from when she was young. I'm not sure but I think her last name was Mochizuki, though it might have been one of her friends who had that name.


I think she has a male friend who carries a sword with him.
She makes friends with a blonde girl in her class who kisses her in class, apparently thinking that it might bring back some of the black haired girl's memories.  
The blonde girl has a twin brother who also kissed the black haired girl for the same reason, hoping that she will regain some of her memories.  


I know it's not very detailed but anything you can think of that matches this description would be helpful.
I believe it is called Otome x Ranbu




  She is your stereotypical airhead school girl, with one exception, she
  has amnesia. She recently transferred into a new school where things
  work different, mainly magic. She is Mochiduki Tsubomi, and she
  doesn’t remember anything before she transferred. Enter yet another
  transfer student – the beautiful yet arrogant bishojo, Izayoi Yukiji.
  She’s after Tsubomi, but why? What does Yukiji want? What mystery does
  Tsubomi hold?