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.

The duke, full of love and kindness, treads carefully around every living being, be it a tender flower or his seductive maid, Alice Lendrott. Were it not for the devotion Alice shows him and the fondness that grows ever stronger between them, the duke would have barely paid heed to his mother's demand: to either lift the dreadful curse placed upon him or lose his family inheritance. Although the duke has no greed for riches, he yearns to be rid of his frightful powers—which cause all he touches to die—for the sake of those closest to him. As the duke, Alice, and their friends enjoy spirited days filled with the ridiculous affairs of the supernatural, the spring deadline looms heavily over them. Nonetheless, the duke refuses to take any shortcuts in this endeavor if it means betraying the trust of his cherished friends.

The attempt to capture the mysterious perpetrator who possesses people ends tragically: Lu Guang is rushed to the hospital in a critical state, while Cheng Xiaoshi is arrested for the alleged crime. In light of recent events, the father of Liu Min unleashes his skilled, ruthless lawyer—Qian Jin—after Police Chief Li Xiao, who is spearheading the investigation related to the photo studio owned by Qiao Ling. It appears that no one is safe from the unpredictable and fatal attacks of the adversary who painstakingly hides their identity. As he tries to learn from his past mistakes, Cheng Xiaoshi must act swiftly and decisively to put an end to this devastating trail of death.

Millennium Research Institute, a counseling office where bizarre requests come in. The head of the research institute, Ichirou Umoregi, also known as Akuma-kun, a genius boy who only appears once in 10,000 years. However, he doesn't know his real family. So Akuma-kun, along with his partner Mephisto III, pursue the mystery of his origin while challenging mysterious cases in this mysterious detective buddy story. (Source: Fandom)