As the new year begins, the senior members of the Light Music Club enter their final year, leaving only Azusa Nakano as a second-year. Concerned about leaving Azusa alone after their graduation, the seniors embark on a mission to recruit new members. Despite their various recruitment efforts like distributing flyers and performing, they struggle to find interested underclassmen. However, a change of heart occurs when Azusa overhears Yui Hirasawa expressing contentment with their current group dynamics and fun activities. With this realization, Azusa decides to hold off on recruiting new members. K-On!! follows the daily high school escapades of the Light Music Club members, from practicing for gigs to engaging in light-hearted mischief, as they aim to make their final year together truly memorable.