K-On! you are not forgotten!
This episode had a nice mix of the selling points of the series: Yui and Ui sisterly love, Sawako and her costume antics, Mio (more on her below, lolz), and a live performance. And I feel nothing was forced this time.
That thing about Mio being in another class apart from friends reminded me of Kagami, again.
About the live performance, the intro reminded me of Fuwa Fuwa Time but I decultured more with this new one. It must be the duet. It's also because I put some weight on the lyrics and it helps that Mio seems to be a sentimental and romantic kind of writer like me. The song is good lyric-wise especially, just that who would take a song entitled "My Love is a Stapler" seriously?!
EDIT: Oops, the intro of Love is a Stapler isn't like one in Fuwa Fuwa Time, it's the intro of Driver's High, the music video of which is the basis of the one in Fuwa Fuwa time. orz lol