I think it's more the 8 ball incident that the intimacy points, because Hikami should also have high points, but she's not aware of the system
Kusora was always kinda suspicious, or rather, she always felt something strange...guess she's very perspicacious, and the box incident might have made her part of the game as a "player" rather than "npc" (if you allow me to use this definition).....i mean, we know that the old lady (Hikami's teacher/master) also have/had to all the functions (shop, stats, etc.), so it's not impossible that there're others "players" too...maybe Kusora isn't a real "player", but she's now aware that something's not right, making her not an "npc" anymore...