Sharu

The protagonist Ryu, born into the Ardrén baronial family, has been unable to use magic since childhood due to “a certain reason.” Branded as incompetent by his father, he is cast out to a separate residence along with his mother and his younger sister, Lena. Although they live modestly, they manage to find happiness—until their mother falls seriously ill. Upon learning this, the father—who has always seen them as a nuisance—plots to have all three of them killed. After discovering the plan, Ryu makes a decision: to defeat his father in order to protect his mother and sister, and to develop the territory he has obtained into the very best it can be, so he can afford his mother’s medical treatment. Thus begins a heroic fantasy of territorial management starring a noble scorned as useless—who turns out to be the strongest of all!

One day, Minami Matsuo, a high school student who dreams of having the suicide uniform she made worn by a man she recognizes as her ideal watchdog, is attacked by a street demon. The moment she wonders if her life, which she set out to make her dream come true, will end like this, her consciousness fades away. When she regains consciousness and wakes up, she finds a strange other world full of steam, pipes, and gears that are like fog. The man who appeared before Minami's bewildered eyes, dashing on his steam bike, was Leon Astor, a man known as the "Marquis of Delinquency," and a vampire! Witnessing his strength and power, Minami sees in Leon the image of the hero of a Yankee movie she saw as a child and her ideal gang leader, and decides to have him make and wear a suicide suit!　However, a shocking revelation awaits Minami as she goes ahead with her dream: A unique love comedy of "delinquent x otherworldly x vampire" unfolds in a vivid steampunk world!