Damn, this was really fucking good. It's hard to get a lot of exposition in when you only have 17 pages, but really good artists like Ishikawa Shisuke are able to write and frame their works so well that the art and atmosphere really adds in to the story. Just the body language, the way the younger sister talks and acts... It's funny, because you read a lot of shorter doujinshi on EX and a lot of them can blend together but this really sticks out as just an excellent little story. It's just the really good art, cute characters, simple but effective lines and plot. Really, really nice stuff. I very much enjoyed this. Thanks so much for the upload OP.