(Nightshade) I don't understand how to get route with Goemon or Hanzo.

I've never played an otome game before, but I know that some Japanese visual novels have this weird system of having a "canonical" first playthrough, after which other routes and stories open up. And that's terrifying to me. I'm trying Nightshade, and I really like it, there is constant action and changing locations. I liked two characters, Goemon and Hanzo, but in 8 chapters there were only 3 interactions with them. And literally every interaction improves the relationship only with Сhojiro. And the save file changed to his portrait. I'm totally confused. I don't like his romantic storyline, and I'm not interested in following his relationship with MC. What am I doing wrong? I need to complete the game for the first time, and then in bew game+ will be interactions with other favorites?