taken from 4chan
>Shortly before Yotsuba collapsed, she had a conversation with Takebayashi about 6 years ago, on that trip to Kyoto. Takebayashi mentions seeing some sisters together, so he asks Yotsuba, if it was she who met Fuutarou on that trip. At the hospital, Yotsuba tries to leave alone, but is stopped by Fuutarou, who holds her and tells her to rest. Then Fuutarou tells him about the situation at school. Then, Fuutarou tells Yotsuba that all the students who were helped by her at the festival, joined together to work together, when they learned that she had passed out. Upon hearing that, Yotsuba starts to cry.
>Once she was discharged, Yotsuba went to meet Fuutarou, who had fallen asleep on the stairs. Then, Yotsuba kisses Fuutarou like Rena, and later apologizes for not having fulfilled the promise made years ago. Then Yotsuba tells Fuutarou, who is still asleep, that he will value his new 'me' more.
>When Fuutarou woke up, he thought it was all a dream.