Thank you for the bug report, I think I have a general idea what could be causing the bug with Hanako staying in your party, so that shouldn't be a difficult fix, if my suspicions are correct.
As for Lady Kumiko's CG I'm a little surprised since something like that probably comes up during testing. It's even weirder that it shows it as accessible but then doesn't show you the scene. I'll investigate and see what could be causing this, but this one might be a bit of a harder nut to crack.
Either way, I'm glad you enjoyed the game!