I liked the church jam session. Similar things happen at my church several times a year. And since I'm the archivist for the music department, I can share one of them with you:
I also like that Ri-chan showed up at the end. After seeing this final episode, I now think that the primary focus of this story was not the Kaoru/Sentaro relationship, but rather the relationship between all three of them. Together they are family, and the bond runs between all three.