At the time of the ceremony of entry to the college, a young boy named Ushino Hayama finds Sara a girl whom he met ten years ago. From this day, a change has taken place in him, and notices that can now control some water. After having succeeded the swimming championships, he discovers deep sea diving. (Source: ANN)

In a stormy night, Mikan and Mom were stricken by lightning simultaneously and switched bodies. In the following days, while Mom enjoyed being a student again, Mikan had to fought with house chores. Meanwhile, Yuzuhiko and Dad were busy looking for a way to switch them back. (Source: ANN)

Ayakashi are strange, supernatural creatures invisible to the majority of people. Though most are harmless, some ayakashi attack humans to devour their life force. Exorcist ninjas are tasked with protecting people from these spiteful spirits. Matsuri Kazamaki is a young exorcist ninja born to a prestigious clan. His childhood friend, Suzu Kanade, is an ayakashi medium—an individual with immense vitality that attracts ayakashi. Matsuri deems all ayakashi threatening and wishes to keep Suzu as far from them as possible, but this clashes with her desire to remain close to them. One day, the pair encounters Shirogane, the King of Ayakashi, who is hellbent on consuming Suzu. As she is about to be eaten, Matsuri comes to the rescue and manages to seal the ayakashi's powers—but not before Shirogane takes revenge by turning him into a girl! Until he finds a way to transform back, Matsuri must adjust to his new, peculiar lifestyle while fighting against hostile ayakashi. Moreover, Suzu is now conflicted about her feelings toward Matsuri—further plunging their relationship into a state of ambiguity.

Natsume Tomoharu is a normal high-school student in every way with one exception: he's being followed by the ghost of his best friend, Misao. After moving into his brother's old house, Tomoharu expects to continue living his normal life but is one day left with a mysterious and locked briefcase without any instruction. At first he plans to leave it in storage; however, his house is soon invaded by multiple groups of people after the briefcase. Although still not knowing the purpose of the briefcase, Tomoharu and Misao attempt to escape with it. From there on, Tomoharu tries to learn the secrets behind the briefcase, the connections between it and Misao, and why it has the power to change the world.