The series focuses on high school student Rentarō Aijō, who in his lifetime fell in love and confessed to exactly 100 girls, only to be rejected by all of them. While praying in a shrine, Rentarō is approached by the God of Love, who reveals that he, due to an error, is destined to have 100 soulmates. However, he also tells Rentarō that if he does not return the feelings of any of his soulmates, they will suffer an accident and die. Not wanting this to happen, Rentarō is determined not to let any of his soulmates die as he meets and dates them all at the same time.