K-ON! Season 2 Episode 5 — Staying Behind!
Published March 8, 2012
Azusa, along with her classmates Ui and Jun, spend time together while the light music club seniors are on their trip to Kyoto. Noticing that Ui would be lonely without her sister around, Azusa and Jun decide to sleepover at her house, in exchange for Azusa helping out with her underclassmen in the jazz club. After spending the night, they wake up to a rainy day. They go to an arcade where Ui hits a home run in a batting game, before Azusa is reminded that she needs to feed Ton. While in the light music club room, the three decide to have a jam session together. The other girls return the next day and give Azusa a keychain, one of a set that spells out "light music club".