Currently the hot spring event is the only way to get to the sex scene with Naomi (also you get a cool sword for Ryen if you don't punch the creep watching Mira and Mirel in the original event).
I hope there will be a way to help them make up in the future without the hot springs, then. I punched that creep with 30 hours of game or so, and now I have 102 hours and am finishing all content.
I'm not willing to re-play 102 hours of content for a scene whose requirement makes me feel unconfortable. The guy from the onsen deserved much worse than a punch, and as i said, I care not about the scene itself. I just wanted to progress in the fox sisters story
It's possible to open the hole in the wall of the secret hot spring. There is a sparkling event where you had the first events about it, when you picked to close the hole before. It's not necessary to restart the game to change that choice.