Golden Time - Season 1 Episode 4 Blackout

After Linda finds them, she explains that she was out on a club retreat with the Festival Club, and brings Banri and Kōko to their campsite. After returning, Banri is greeted by Nijigen, Mitsuo, and Chinami, who are all relieved to know they are alright. Later during a break, Banri, Mitsuo, and Chinami get together to talk, but they are interrupted by Kōko, who begins to berate and belittle Chinami, causing Mitsuo to leave with Chinami and leaving Banri to comfort a remorseful Kōko. After class, the pair once again encounters Linda, who invites them to participate in one of the Festival Club's dance rehearsals. Banri decides to join, while Kōko considers the idea. Later that night, Mitsuo tells Banri he will settle things with Kōko, because he wants to pursue a relationship with Chinami, and the next day Mitsuo flatly rebuffs Kōko's affection in front of Banri. Kōko asks Mitsuo if their time together meant nothing to him, and Mitsuo replies that while he treasures their time together, he only sees her as a childhood friend. Kōko angrily yells at him to forget their history, driving Mitsuo away. Kōko yells at him to disappear, but realizes her words are hurtful to Banri, causing her to continuously apologize in tears. After a few hours, Kōko and Banri are invited by a girl called Nana (most likely a reference to Nana Osaki from the manga and anime NANA) to her concert. Kōko goes to vent her frustration, but is thrown out, and spends the night at Banri's apartment. Kōko reveals she needs him, while Banri confesses his love for her. After she leaves, she texts Banri, encouraging him to not forget about his lost memories, which motivates him to return to his home in Shizuoka, where he finds a scrapbook containing pictures of himself and Linda in high school together. (Source: Wikipedia)