Aibou Seasons 11, 12 & 13

I thought only the older seasons aren't subbed but the newer ones should be up somewhere. Did you try the most famous sites like d-addicts and asiatorrents?

Dramanice has season 11 subbed and the first 9 episodes of season 12.  Like you I am searching hard for the rest of season 12 and all of season 13 subbed.  This is such a great series, I'm baffled that all of the seasons aren't subbed and being watched on lots of fan sites.