When I am trying to complete one of my seven routes and realize that if I do not get the chance to propose and marry the one I want within even just the first week in game, the game smacks in a random romantic interest/boyfriend or even worse fiance stage townie she may not even know to her list. I am glad I just done three of seven already, including Yuuma. I found her quite easily but by the time I secured her, I am forced into a two-timing escapee where I have to hide her and keep away from RNG's newest partner, the Swains for a good while and hope that she gets a Clean Slate reward for 25,000 XP just to clear her bad rep and a clean pass!
I made sure Yuuma ignores calls from them until she is cleared because if she goes to their parties, or get too close to the alleged original partner (about the radius of an entire lot), they will know that I stole her from them and will try to pounce me. I even made sure that the game does not force her to use a particular social that makes her admit that she is a cheater even though she didn’t actually met the Swains due to her "Good" trait, which would then cause me to retry the whole route. I hope I will remember this quick enough for future routes, especially the ones with romance-related traits and try to increase my Social and Romance sub-branch options. A similar thing happened to Hitarashi while I was romancing; the game suddenly punishes me with no notice, only an update on the sim's simology for not romancing my waifu quickly enough with a random townie, possibly an "inappropriate" nerdy schmuck.
I then fought said schmuck twice for attempting to steal my girl by decreasing the relationship in front of her, and then I leave him be and take the waifu back to safety a while later for storytelling purposes. He didn't swore revenge on me for the rest of the route because I gave him a life lesson. Eventually she stopped being a tsundere after about the fifth time during her route and she let me have her as a true wife. Had I left Hitarashi to her own devices for too long, she would eventually have someone else and fail the route, forcing me to retry.