『舞一夜』的故事发生在小茜等人刚来到京城不久,当时小茜心理上正处于矛盾边缘,已决定留下来守护京城,但又不知如何尽力;此时与八叶之间的关系也处于雏形的培养阶段,突如其来的变化使小茜的感情变得十分脆弱,与八叶也出现了莫名的隔阂。就在小茜产生动摇的时刻,她眼前出现了一位携雨而来的谜样男子...
One rainy day, Akane crosses path with a kind young man who tacitly offers to her his coat. On their second encounter, he confesses that he has no recollection of who he is, his name or his past, but feels contented by just being with her. Besotted, Akane sets out to find his name, and to unravel his enigmatic connection with a famous cursed dance rumored to kill anyone who attempts to perform it.