To Another World Middle school student Yuya Tenjou has been bullied since childhood due to his obesity, even by his own parents, who prefer his more attractive brother and sister. Yuya lives alone in a house he inherited from his grandfather, the only one to treat Yuya kindly. One day he saves a girl, Kaori Hojo, from thugs but is badly beaten in the process. Later, he discovers a secret portal to a cottage in another world that operates like a video game. The cottage comes supplied with powerful weapons, and while experimenting with his skills, a powerful monster appears outside the cottage's magic barrier. From inside the barrier, Yuya kills the monster and immediately gains 100 levels that evolve his body, making him tall, muscular and handsome. Using a skill to trade items for Japanese currency, he buys new clothes before returning to Japan for his first day of high school. His former bullies are stunned by his transformation but, along with his jealous siblings, still attempt to return to bullying him. They are interrupted by the arrival of Kaori, who somehow immediately knows he is Yuya.