Starting from where Episode 11 left off, Lala accepts Haruna's feelings and vows to help achieve her love. At the water park, Saruyama observes Rito and tells him that he has changed after Lala came around as Rito is more comfortable being with girls. Rito tries to understand the values of Lala. Nearby, Run and Kyouko perform a concert when an alien amoeba attacks and suffocates everyone. Lala tries to rescue Haruna, who gets eaten by the amoeba, but suffocates. Rito sacrifices himself to rescue Lala and Haruna. As Haruna and Lala try to rescue Rito from death, Rito sees flashbacks and realizes that he loves Lala too. After the amoeba was defeated, Rito tells Lala in private that he loves her, but really loves Haruna too. Lala proposes a solution by having Rito marry both of them. Before Rito could oppose, Lala blasts Rito to Haruna so he could confess to her. Oshizu accidentally rips Haruna's swimsuit, making her run away when Rito confesses to her. His confession reaches Nana, Yui, Mikado-sensei, and Run, inspiring Lala that Rito should marry them all.