Apollo casts a warning in the sky to her sisters to trust no one before succumbing to her wounds. Lune attempts to finish her but is stopped by Nikaidō. Keima, Diana, Elsie and Haqua have Apollo taken to the Katsuragi household where they discover the magic dagger used on Apollo and Kanon is ancient Weiss magic and the culprits are Vintage, a group of demons who wish to resurrect the Weiss. With Kanon having a week to live, Keima must find the other four goddesses to heal her before Vintage gets them. To accomplish this without incident, Elsie disguises herself as Kanon and Keima tricks his mother to go to South America. Partnering with Haqua who is disguised as Elsie, Keima uses the rumor of Kanon's confession to see the reactions of his prior conquests, who will act jealous if they remember falling in love with him. Keima narrows his suspects to Ayumi, Chihiro, Shiori and Tsukiyo Kujyo, who were all embarrassed around him. When he at first thinks Yui Goido is not a goddess host due to not remembering him, a confused Keima is surprised when Yui confesses her love for him, which Shiori and Haqua mistake the cross-dressing Yui as a boy who is being intimate with Keima. With his five suspects, Keima must now make them fall in love with him again which will fuel the goddesses' powers and determine if they're a host.