Taishi Orizue, a socially misfit nerd who studies in the biology department of a certain university's Faculty of Science in the Kanto region with Daisuke Kurii, who aims to become the chestnut girl harem king of another world, is suddenly transported to another world one day. Early on, they are attacked by a flock of cockatrices, but they are the inheritors of the Orizue style of ancient martial arts and are experts in survival techniques. They clear the problems one after another, but then chestnut girls appear...