The plot begins after K-On!! episode 22. After they are accepted by the same university, Yui, Ritsu, Mio and Tsumugi try to figure out a present to give to Azusa before they graduate, and they all decide to go to London for their graduation trip. Upon arriving, they end up having to give a performance at a sushi restaurant after being mistaken for Ritsu's friend's band, Love Crisis. As the girls enjoy the sights, Azusa seems to be rather cautious around Yui's odd behavior, having almost walked in on their plans before. Later, the girls are asked to do a performance for a Japanese Pop Culture Fair, where they are soon joined by Sawako, before they catch their flight back to Japan. Upon returning home, the girls perform a special live concert in their classroom. Afterwards, Yui, Ritsu, Mio and Tsumugi work in secret to prepare a special song for Azusa, which they present to her on the day of their graduation at the end of K-On!! episode 24.