Yugo Aosaki

In this world, creatures like vampires and werewolves still walk about, but Aya Rindo can’t say the same for herself. This beautiful disembodied head, carried by her maid Shizuku Hasei, is a detective in search of her stolen body. One evening, they meet half-human Oni Slayer Tsugaru Shunichi, who offers a lending hand. Now, the trio is traveling through Europe, solving mysteries along the way.

This work depicts a "five" locked room mystery drama about two high school students, which develops in the first train in the early morning, the family restaurant after school, and the gondola of the Ferris wheel. A word that suddenly changes from everyday life to extraordinary, a psychological warfare on searching each other's minds. Youth, a fragile blue human figure, is depicted in a peculiar situation called a locked room.

Gotenba Tori and Katanashi Hisame are private detectives who work together and run the detective agency Knockin' on Locked Door. They are partners and, at the same time, rivals. They use different methods to solve cases and also have different personalities. Gotenba Tori is good at solving cases in terms of how the case took place. He always wears a black turtleneck regardless of season, and he doesn't hesitate to express his feelings. Meanwhile, Katanashi Hisame is good at solving cases in terms of why the case took place. He is guided by common sense and always wears a suit with glasses. These two detectives with different personalities take on the most difficult cases and work together to solve them.