Minazuki-ke no Iinazuke ~Juurokusai no Tanjoubi, Honke no Toushuu ga Mukae ni Kimashita~

Rokka Mizunashi, a young girl, has lost her father, the only family she had left, to a strange illness, leaving her all alone in the world. Rokka has lost her reason for living, and a young man claiming to be the head of the Mizunashi family appears before her and tells her a shocking truth: "I am a 'forgiven bride' to you. Rokka had never known anything about her father until this day. About her father. The family code. The fact that the Mizunazuki family is the "descendant of a celestial maiden" as represented in the legend of the robe of feathers.