The storyline follows Jun'ichiro Kagami, whose sister Suzune is mad at him because of his complete disinterest in the world that is real. Suzune compels him to go on work as a physics teacher replacement in exactly the same high school from which he graduated as Jun'ichiro is interested in only games, manga and anime. Jun'ichiro Shows himself a hard-working and competent instructor who comes with techniques according to the apparently worthless knowledge inspire and he got as an otaku to educate his pupils.
The key character as well as a 2 4-year old hard-core otaku who spends his days until he's driven by his sister to be a teacher at his alma mater at home trying to to enhance his anime site. Jun'ichiro is a physics key who printed a paper that triggered a chaos that is huge in the world when he was only 17. It proposed a hypothesis to develop a teleportation device in the exact same style of Doraemon's "Anywhere Door". All attempts to disprove the hypothesis so significantly have failed, though it might take centuries for human beings to come up with the technology required to to put together it despite being ridiculed by professors.
Despite being scouted to work on the main research centers on the planet, Jun'ichiro promises to suffer from an illness called "YD" that "only lets him do what he yearns to do", so he rejected their offerings. Yet, after spending several weeks working as a teacher, he's convinced by Koyomi Hiiragi to work on her college. Since then, his time divides between finding ways to incorporate one into the other, typically through using competitive game titles and emphasizing his by-lines and occasionally using his unusual techniques to reform isolated pupils.
Jun'ichiro sister who's constantly mad at her brother's jokes. Her avocation is bat training, and she's the sole man whom Jun'ichiro actually dreads. She prohibits Jun'ichiro from purchasing anything without her blessing and is also responsible for most of the household's financing. Despite all of the problems he causes her, Suzune needs to to deal with him eternally and is quite fond of him. She's a custom of hitting on the others, generally Jun'ichiro, with her bat when she is upset or mad together.