This isn't true at all. I will tell you, Mio's arc ends at episode 3 if you don't know. 4th is a bug chapter which means there will be at least 8 episodes left over. 4 episode each for Kanon and Dandere? I don't think so. Shiori chapter especially lacks a lot of events, so both will only last about 2 episode maximum. This means, it is more logical that we will have more girls; I mean, there was previous PV where it shows animated scene of kissing which included Chihiro, teacher, doll and hakua.