Hiiro no Kakera (緋色の欠片, lit. "Scarlet Fragments"), is a Japanese visual novel created by Idea Factory directed at the female market, known as an otome game. A 13-episode anime adaptation by Studio Deen aired in Japan between April and June 2012 and was licensed in North America by Sentai Filmworks. A second season, Hiiro no Kakera: Dai Ni Shō (緋色の欠片 第二章, lit. "Scarlet Fragments: Second Chapter"), began airing on October 1, 2012 to December 23, 2012.
Tamaki Kasuga has supposedly gone to live with her grandmother after her parents are transferred overseas. But the real reason for her arrival is that she must continue the role, handed down from her ancestor Princess Tamayori, to seal the sword Onikirimaru. Five young men serve as her guardians against the mysterious Logos.