I thought this was very good and moving. I don't watch Tohou, and based on the numbers of doujin's with this pairing I'm guessing it's not very popular, but I thought it was great.
Well pretty much anything by Personal Colour is great, so that's a thing. Plus, the two usual pairings for Kanako are Sanae and Suwako, with the latter being a bit more obvious, where the two are sort of surrogate parents to Sanae. So this pairing is a little less common as a result, but certainly not a bad one.