Als die Mitglieder des Kulturklubs in ihren Raum kommen, stehen Namen und eine Uhrzeit an der Tafel geschrieben. Was hat das zu bedeuten?
On the day before Winter break, following a brief period of peace after the unleashing of desires, a new phenomenom takes place in which Yui and Iori temporarily revert to a younger age during 12pm and 5pm that day. After returning back to their normal age, they lose memory of what happened, but remember things from when they were that age. Later that night, a second Heartseed appears before Taichi through his sister's body, tasking him with watching over the others and warning him not to tell the others about his existence. The next day, Taichi stumbles upon Yui who is argued at by an old karate rival, Chinatsu Mihashi, over breaking a certain promise which she can't remember. As the gang meet up at an abandoned building, this time Himeko and Yoshifumi shrink, with the now ten-year old Yoshifumi likening Yui to a girl named Nana Nishio. After reverting to his normal age, Yoshifumi explains Nana was a girl he went out with once before she moved, leading him to be conflicted over how his feelings for both her and Yui stand. The next day, as Taichi and Himeko watch over a 14-year old Iori, Himeko voices her worries.
2学期の終業式、放課後に部室にやってきた5人は、
黒板に太一以外の4人の名前が書かれているのを見つける。
それが意味するものを考えているうち、
伊織と唯の身体に異変が起き、なんと2人は子供の姿に戻ってしまった!
太一たちはこれはまた<ふうせんかずら>の起こす新しい現象だと考えるが……
Con Fuzen Kazura desaparecido, el grupo disfruta un poco de tiempo libre, pero alguien que visita a Taichi aparece para causar nuevos problemas.
在慾望解放現象結束後不久,寒假的前一天,時間逆行現象開始了。太一偶然看到唯與以前空手道的對手三橋千夏爭執,而唯也發現青木在時間逆行時,把她誤認為是名叫菜菜的女孩…