Sawada Honoka is a 14-year-old girl who is very timid. She easily gets bullied by other classmates. Honoka is a non-believer in God, Angels, and Devils. Though one day, a devil baby was dropped into her room while she was sleeping. What will Honoka believe in now?

Crossover movie between Aikatsu and PriPara.

“我曾以为，只要拥有那份力量，就能守护一切。”
位于迪南地区东北部，拥有强大军事力量的海兰德王国。隶属于该国少年兵部队的少年——主人公利柳与挚友乔伊，两人曾仰望同一片星空，同宿于一个帐篷，并坚信着同一个未来。只要这场战斗结束，只要天一亮，就能回到那个平凡的日常。然而这份心意终究徒劳，两人终究被卷入了由战火引导的命运漩涡之中。无力的少年们，获得了强大的力量。在 108 颗星辰格外璀璨的夜空下，怀抱着无解的问题，少年们，将遵循自己的信念启程前行。

Gemstone, the Mermaid's Scale, appears in a secret, underground auction. The queen of the underworld coerces Lupin into stealing the rock for her. Quickly discovering not only that the stone is a forgery, but that the real Mermaid's Scale is part of an unsolved riddle that leads to transcending mortality!