Wonder how many times I've re-read this... It's a wonderful doujin, one of my favourites even though I'm not even that into EiTeru. The sense of Eirin's devotion to Kaguya is depicted really well, and the art's great too.
Actually, I watched the Ghibli film based on Kaguya's legend recently, and I couldn't stop thinking about this doujin - I liked it way better than the film... (-_-;;)