What? First level up your charisma. Then talk to them, and give them Plushis from the arcade, Complement and Flirt with them. However the most important thing is to have something in common with them. In other words start building up your skills. Like gaming, physical, art, cooking, writing, and dance. You'll end up having one of those in common. Which when you talk to them will build up affection. Most importantly they have to swing your way. Because if they dont all you can be is friends, and that's for all NPC's. Literally even my harasser likes me. Because I be taking photos of myself and uploading them to Elkbook. Building up my photography skill. Which means I can talk to them about it.