I've just started out the game and one thing that kinda feels weird is the use of the full Japanese name in socialization.  Not sure if it crops up elsewhere, but it'd be nicer to get either lastname-san or a first name/given name in the Socialization screen.  So instead of "Kitano Oka shares a secret from her past" it'd be "Kitano-san shares a secret" or "Oka shares a secret."  Something like that. 

Good idea - maybe swapping from the honorific to the more familiar forms as the relationship increases.

This would start to become a little confusing when you have many idols; maybe having a window show up when you hover over the name would work.