Kouta Shibaki, an average high school student who is straight, is unfortunately labeled as a pervert by his peers after a bad accident. Kouta's worst fears come to life as he becomes estranged from girls at school. One day, Kouta comes across a strange book in the school library that has the power to call forth witches. Out of desperation and boredom, Kouta decides to test the book's magical abilities. To his surprise, an apprentice witch named Rurumo Maji Mojiruka appears before him. Kouta agrees to help Rurumo with various witch duties, hoping to spare his soul in return. Majimoji Rurumo revolves around Rurumo's attempts to persuade Kouta to use 666 magical tickets that can grant wishes. Kouta is unaware that using the tickets shortens his life span every time he makes a wish. With the help of Rurumo's partner, Chiro, Kouta must make a choice between helping Rurumo become a witch or saving his own life.