Asuka is Kazusa's dog partner, Asuka was originally a very mean and vicious dog but Kazusa proved to him through persistence and love that he truly cared for him and Asuka became the sweet dog he is now. Although Rino was all alone Asuka reached out to her and despite being hurt by her he carried on in his career and still reached out to her. After the car accident Asuka can no longer use his hind legs but by using a "wheel-chair" for them he is able to walk and play like he used to.