So you know how girls like Bunny, Juliet, and Tina Reed have 5 stars, where you give them gifts to increase affection, upgrade them, and you get a scene and the girls stats go up, yet, some other girls have only 3 in the harem menus? Basically Bonnie/Plaige are 3 star girls who are getting more stars, or upgrade scenes, and higher stats. You'd upgrade them same as any other girl.