This was a strange story, first the POV, it's been a while I had a good story told that way. I really enjoyed how it was game-like with the narrator telling the next move. How Rie treated Yuki, I almost wanted to get away thinking it was too much, honestly the red cross on the right corner seemed very tempting but I'm glad I stayed long enough to see how they got rid of the first sister and went for Kanon. The cookie eating part was so annoyingly nice, I wanted a cookie too just to make her angry. I can't believe Kaede thought his sister was like a cockroach! And the limited edition of Snoopy was a smart move.
Let's not comment on how you stick the talisman up the rest of sisters' asses.
Anyway, you did great job weirding out the readers