With Yui at home sick with a nasty cold, the Keion club faces a crisis for they only have four days left before the school festival performance. Mio suggests that Azusa practice lead guitar just in case Yui doesn't get better before the festival. When Yui (who is really just Ui in disguise) shows up, everyone is shocked at how fast she has recovered. It isn't until Ui screws up her plan to act as Yui by adding "San" to the end of Ritsu and Mugis names. Sawako-Sensei also points out that she knew all along it was Ui because of the fact that her breasts are bigger than her sisters. Then soon aftewards, the real Yui shows up, claiming to be all better but starts sneezing all over the place again. When Yui is resting, she suggests that maybe it's all for the best that she doesn't play in the show along with the rest of her friends in the club. Azusa disagrees and says that if Yui won't be able to play in time for the performance at the school festival then the band will just drop out. Mio announces that she has a better idea and tells Yui to not attend the Keion club until she is fully well rested so that they can all perform together.
Finally the school festival has arrived and everyone is bustling with excitement over all of the decorations and stands and varieties of events. Meanwhile all of the members of the Keion club are wondering where Yui is as she had sent a text message to Tsumugi saying that she is all better and that she will definitely be able to make it. When Nodoka comes in and tells them all that they will be performing at 1:00 PM, she notices that Yui is not in attendance but disregards this fact. Mio is surprised by this, but Nodoka goes on by telling them that when they were little, Yui used to collect all these baby lobsters and keep them in Nodokas bathtub. Nodoka then goes on to telling the Keion club that once Yui has her mind set on something, she will complete the task no matter what it takes. Sawako-Sensei walks into the clubroom and Ritsu questions her as to where she was until now to which she replies she was making "cold weather" Yutakas for the band. Showing off this new outfit is non other than Yui who appears to be alot better. Azusa tells her that everyone was worried about her. Yui walks over to Azusa and gives her a nice hug, apologizing for making her worry. When it's time to get ready for the performance there's just one problem now. Ui took Yui's guitar home so now Yui is without an instrument to play and the performance is almost ready to begin. When Sawako-Sensei offers a different guitar, Yui turns it down because she says that without her "Gui-ta" she cannot play it. There's quite an amount of students attending the performance for "After School Tea Time" (Keion Club) and the crowd is buzzing with excitement as they start playing with everyone in their proper places except Yui who has ran home to get her guitar while Sawako-Sensei fills in for her. On her way back to school, Yui recalls of the first day of her entrace ceremony into high school and wondering what she should do and if she will continue living this lifestyle even in adulthood. Yui finally decides that she has found something she can commit to and that's within the Keion club, playing guitar. When she finally reaches the schools auditorium, she gives her sister a peace sign before getting up on stage and joining her friends. She thanks Sawako-Sensei for filling in for her while she went home to get her guitar. Yui then turns to face her friends and apologizes for once again letting them down. However, Ritsu tells her that she is liked by everyone and thus prompts everyone in the audience to start cheering her on. Yui addresses the crowd and tells them how they started the Keion club and their goal to perform at the Budokan someday and all the fond memories the group shared. Announcing that this stage in the auditorium where they are now is their own Budokan performance they will do their best. The Keion club plays the tune "Fuwa Fuwa Time" which was the first song they ever performed live before an audience. After the song is over Yui announces that she loves Keion and wants to play another song but Nodoka says that their performance is over already.