Thumbs up if you are frustrated because Hoshino Ai's plot hasn't developed at all since the first episode of the first season. This anime is just a huge bait! We have to suffer through random plots related to Hoshino's children in order to find out about the circumstances of her life, which is never shown in the anime. My only goal now in watching this anime is so I can come here and tell you exactly which episodes to watch in order to skip all the uninteresting episodes and get to the actual main plot: Hoshino Ai's true story.
Season 2 so far brought a ton of new characters, and barely any screen time of the main characters, and also has brought NOTHING to add to the main plots that were unsolved in season 1. And I'm not even disappointed, since Season 1 showed us that this anime is all about baiting us and beating around the bush.
I'm expecting to be back to you around episode 10 or so, when maybe they remember to bring back Hoshino Ai's unsolved mysteries.
[EDIT] I'm back exactly where I predicted! The very last minute of episode 9 finally had some development! So on episode 10 you will find something hinting at who their father might be. BUT the big surprise happens at the LAST MINUTE OF EPISODE 11! I'm not very hopeful about any actual development for this season, but I won't deny that the plot twist was a nice touch.