K-ON! episode #12
Yui Hirasawa has a strong fever and needs to stay at home. Her sister Ui Hirasawa takes care of her as much as she can, but both know that if she won't recover soon, her club's band misses a member for the upcoming school festival.
At school, Ui discusses it with her classmember Azusa Nakano who is also in the Light Music Club. All of the sudden, the upperclassmen Ritsu Tainaka and Mio Akiyama visit the freshmen class to discuss Yui's absence with them as well.
While Mio and Azusa blame Ritsu to be the cause of Yui's illness since she was sick just recently too, Ui sees the problem in the yukata their teacher Sawako Yamanaka prepared for them for the concert the day before. Azusa, Mio and Ritsu remember how they tested many other costumes and how fond Yui was of the yutaka. Ui tells them that her sister spend the whole day in it and caught her illness most likely at that time. Mio asks Azusa to prepare Yui's part as well, just in case she would not show up in time.
The next day after school, the band practices with Azusa playing Yui's part with no problem. All of the sudden, Yui showed up, healthy and ready to practice too. The rehearsals however turn out to be way too perfect, making the other original members, Mio, Ritsu and Tsumugi Kotobuki, very skeptical. Sawako lets the cat finally out of the bag and proves to everyone that Yui is actually Ui in disguise.
With her cover being blown, Ui apologises and excuses her actions with the will to help her sister out in every way. At that moment, the real Yui shows up but it turns out she is just as sick as before and absolutely unable to make music. Although she tells her band to go on without her, Mugi and especially Azusa struggle with the idea. Mio banishs Yui from the clubroom with the intention for her to recover properly and be able to play with them for real.
Finally, the day of the concert is reached. Yui is still absent from school and the apprehensions are growing. The band is unable to come to a decision. At that moment, Nodoka Manabe shows up to check if the club is complete. After she marked it as complete although Yui is still missing, she tells them a story about Yui collecting a whole bathtub full of lobsters when they were kids as a proof of Yui's habit of making everything somehow a success once she sets her mind on it. Just at that moment, Sawako appears with a new version of the yukata, proudly worn by the one and only Yui herself.
After Yui apologises to everyone, especially Azusa who was the most worried of them all, the band decides to move to the auditorium, just when Yui notices her guitar is missing since she forgot it at home. Refusing Sawako's guitar because she wants to perform with her own, she rushes towards her house.
Just before the concert starts, Ui meets Jun Suzuki in the auditorium. The concert starts with "Calligraphy Pen ~Ball Pen~", but Yui's part is played by Sawako. In the meantime, Yui reaches her home, grabs her guitar and rushes back to the school, running the same route in the same way she did on her first day of high school over a year ago. Overflown with thoughts, she realises that the Light Music Club turned out to be the most important aspect of her life in such short time, giving her a place to be finally able to be important for others and where she is secure and contented.
Just as the first song ends, she reaches the stage. Sawako leaves the rest to her and leaves under brawly applause. Yui, out of breath and conscience-stricken, starts crying, but the rest of the band calms her down and builds her up since she is just as important to them as they are for her.
Afterwards, being complete once and for all, they play "Fuwa Fuwa Time" and the performance is well reveiced. After the song finished, Mugi starts an encore with Ritsu, Mio, Azusa and finally Yui joining one at a time.