Is there a difference if you pick a different answer when you have the chance to confess? Will it derive a route where the other confesses instead? I was just wondering since Hikaru says he will take care of it himself with his idol ways so I just curious
Yeah. If you confess at that time, you confess first. If you wait it out some more (while continuing to increase his heart stats), the guy will eventually confess. This applies for all, with the exception of Toru-chi'route (in his route, both him confessing / you confessing is in 1 scene).