To prepare for reincarnation in another world, Kelvin gives up select memories from his previous life in exchange for powerful abilities, additional skill points, and an S-class summoner title. As a bonus, the goddess facilitating his rebirth, Melfina, offers him a choice of any companion to give him a head start in his summoner role. Kelvin—who has fallen head over heels for Melfina at first sight—promptly chooses the deity, confident that his passionate feelings for her will resurface even without all of his memories. Kelvin embarks on his exciting new journey with Melfina as his guide. However, in order to summon his beloved goddess' physical form, he needs to acquire significant amounts of mana points—and the best way to accomplish this is to level up by fighting strong enemies and making contracts with even stronger companions.

Everyone has a dream they strive to achieve, and so does the musically talented Kanon Shibuya. However, due to her stage fright, Kanon fails to make it into Yuigaoka Girls' High School's music program and instead ends up in the general curriculum. Even though Kanon makes the conscious decision to quit music altogether, her classmate Tang Keke rekindles Kanon's passion for music with her own: a passion for school idols. Although Keke and Kanon try to form a school idol group, their effort meets strong objections from Ren Hazuki, the daughter of the school's director. Even so, the girls soon visit the director, who allows them to set up their school idol club under one condition—they must win first place at the Yoyogi School Idol Festival. The resilience of these aspiring idols is put to the test as they face the challenges that come their way. Throughout their journey, the girls make new friends and meet new members that join them to become the dazzling idols others can only imagine.