Aimo isn't being released as a single, the Ranka single is Interstellar Flight.
http://gabrielarobin.com/221/ranka-l...-single-tracks
Cat Diary was the ED for 11, I expect Interstellar Flight to be showcased nicely in next weeks episode. After that we get the May'n/Sheryl cd single of Lion/Northern Cross which are the new OP/EDs for the second half of the show. Lion is a duet with Megumi/Ranka. Will probably be one more single after that I reckon... because I'm betting a song or two towards the end will play a big part of the show..