why not add some other girls that we interact with, like the coffee shop girls, to the 21 panels?
The characters of HR are separated in three categories.
The main nine heroines, who live with you and get most of the focus.
The side heroines, who have some story and events.
And the EXTRA characters, who are just there for support roles. These don't have much story, or events, and are tied to someone else entirely. That's why they don't get their own profile, hints and stats.