Rentarou Aijou has confessed to (and been rejected by) 100 girls in his lifetime. On the last day of middle school, he visits a shrine and prays that he get a girlfriend during his time at high school. Suddenly, the God of Love appears and tells Rentarou that the reason for his non-existent love life is because everyone is only supposed to have one soulmate in their life, but due to an error on the God of Love's part, Rentarou is destined to have 100.