You should check out Ryuhei's dad, Yusaku's movies and tv if you haven't already, been watching the tv show Tantei Monogatari a little bit and have watched The Family Game (movie)

I think we'll see some more Mahoro in one form or another, whether that's tv or a movie....or both!..........do you know if there are more books around these characters?

Also, I can't wait for The Great Passage!