The first installment of the new Uta no☆Prince-sama♪ original film series.

In 2079 the birth of the brainwave instrument BrainStation triggered the fourth industrial revolution. Mankind has ushered in a brand new era-the "virtual cyber age". Through the use of a BrainStation, people can connect to an all encompassing cyber world. This virtual world is constructed like a neural network and the entire system is controlled and dispatched by the master brain Watson. However, over time issues are starting to surface: many people can't distinguish between virtual and reality, leading to psychosis and long-term addiction to the virtual world. (Source: QQ, translated, edited)

After a year in America, Kurisu Makise returns to Akihabara and reunites with Rintarou Okabe. However, their reunion is cut short when Okabe begins to experience recurring flashes of other timelines as the consequences of his time traveling start to manifest. These side effects eventually culminate in Okabe suddenly vanishing from the world, and only the startled Kurisu has any memory of his existence. In the midst of despair, Kurisu is faced with a truly arduous choice that will test both her duty as a scientist and her loyalty as a friend: follow Okabe's advice and stay away from traveling through time to avoid the potential consequences it may have on the world lines, or ignore it to rescue the person that she cherishes most. Regardless of her decision, the path she chooses is one that will affect the past, the present, and the future. [Written by MAL Rewrite]

It is the new year, which means that the senior members of the Light Music Club are now third-years, with Azusa Nakano being the only second-year. The seniors soon realize that Azusa will be the only member left once they graduate and decide to recruit new members. Despite trying many methods of attracting underclassmen—handing out fliers, bringing people into the clubroom, and performing at the welcoming ceremony—there are no signs of anyone that plans to join. While heading to the clubroom, Azusa overhears Yui Hirasawa say that the club is fine with only five people and that they can do many fun things together. Changing her mind, she decides that they do not need to recruit any members for the time being. K-On!! revolves around the members of the Light Music Club as they experience their daily high school life. From rehearsing for concerts to just messing around, they are ready to make their last year together an exciting one! [Written by MAL Rewrite]