I lol'd the moment I realized that "love letter" was just lyrics for a song by Mio. That was just awesome. Mugi got some more focus in this episode; something that should've happened throughout this series so it was nice to finally see something to that effect here. And Yui coming in and making the clubroom a little more lively like that at the end just brought a smile to my face. A nice way to end it
I like this episode, it's basically all Slice of life but with alot less moe fluff (to me anyway) then what I came to expect given how the majority of the rest of the series has gone.