Monochrome Factor

Synopsis

Akira, Kengo, and Aya are invited to Haruka Kujou's house, where they learn the secrets of the Kujou family. The previous head of the Kujou house, Shinnosuke Kujou, had experimented with devilish experiments and rituals. The group is then attacked by two sealed servants of the Kujou house, Kyou and Rin, who had escaped by manipulating Kengo. Akira and Aya fight the two, during which Aya reacts to her Kuresame, giving her samurai armor and a katana for use. Akira, Aya, and Shirogane successfully exorcise the two after hearing their history, in which they were involved with Shinnosuke Kujou's evil rituals. However, Nanaya had saved them from pain by possessing them with Kokuchi. After, Haruka befriends Akira, giving Akira another friend besides Kengo, who is, comically, still tied up in the Kujou house's basement.

(Source: Wikipedia)