In this story, the protagonist, Nagayama Shu, transmigrates to Japan and lives with his older sister. He initially plans to live a peaceful life, attend Tokyo University, and manage his dilapidated dojo, eventually becoming a sword saint. However, his life takes an unexpected turn as he encounters various eccentric characters, including students from a notorious school known for its violent tendencies. He also discovers his sister possesses extraordinary abilities, as her bamboo sword can even conjure ice. This sets the stage for a blend of slice-of-life, action, and supernatural elements as Shu navigates his new reality.