Himeko Tsuruta is a second-year student at Shindouji Girls' High School. She has been together with Mairu since middle school. She is the shy type personality person and always cares for her team members especially Mairu, due to their strong bond in friendship.
Her ability is to linked with Mairu. Mairu has the option to impose a Han restriction (eg. 2 Han or 3 Han) on herself the moment she opens her hand, if she wins with that hand then Himeko will win that same round with double that amount (eg. 4 Han or 6 Han, respectively). This Han restriction is not limited to Yaku, dora can also be used to elevate her Han values. If she doesn't win then Himeko will almost never win; though, in the rare event she does, it'll probably only be 1 Han. If she doesn't link with Himeko then their hands will be unrelated. Also if Mairu has extra han left after her binding, Himeko cannot use them.