Yui Sakakibara

Takumi Nishij? suffers from intense delusions as a result of his apparent schizophrenia and the extremely secluded lifestyle he lives as a hikkikomori. One day he accidentally stumbles upon a gruesome murder scene, a part of a chain of events called "New Generation". After this, his life gets caught up in these events, and he meets a bunch of increasingly insane anime girls with swords. (ANN)

Kamisaka Haruhi, having been rescued by a mage when she was young, longs to be a mage herself. So she enrols into a special school that also teaches magic. Together with her rival/best friend, Hiiragi Anri, she studies magic while searching for the boy, who saved her years ago — to give him chocolate on Valentine's Day. Source: ANN