Himeka is Eita's "ex-girlfriend", who has a one-sided crush for him. Himeka is a girl who has teenage delusions, believing her ex-life was "Burning Princess Saint Dragon Lady of Dawn". After she saw Eita lose control of himself and revealed some of his teenage delusions, she believed that Eita and she were a couple from her ex-life. However, while not being a delusional teen, Himeka is really quiet and answers usually only by nodding. Other girls often call her "princess" .
Source from Wikipeida