The author has read Fruits BasketAcross her Junjou and Sekai worlds, we have the names, Kisa, Hiro, Yukina, (Yuki) Hatori, and Ritsu. Someone's a FB fan.
Yukina is going to get in an accident that results in a facial scar
- Kisa is afraid he only likes Yukina based on his good looks, so a good way to prove that wasn't true would be to give Yukina a scar, via car accident or some other thing. It would prove to Kisa, once he obviously still loved Yukina, that he didn't just love him because of his beautiful face.