Thank you so much for your reply!
I'll consider the female character issue—they'll only appear as secondary characters.
And I'm sorry but my current plan is to remove Kyouji and Shoutaro and redistribute some of their original storylines to other characters. I feel they belong as a pair and shouldn't be part of Hiroyuki's romantic arc (I'm a pure love advocate).
Later on, I might arrange a special way for them to make a comeback? But I don't have any ideas yet ORZ.