Fuutarou Uesugi, a high school student, tries his hand at working as a tutor because he is both impoverished and educated, and it turns out that the job pays quite well. Itsuki Nakano, a new classmate with whom he had a somewhat rocky start, and her four sisters, Ichika, Miku, Nino, and Yotsuba, are the students he is expected to teach. The quintuplets, despite their appalling test results, are not only exceedingly erratic and obstinate, but they also have no desire to learn anything. But in order to make positive changes and finally manage their grades, Fuutarou must first gain the confidence of each of the five sisters.
