Also known as: 川尻早人
A pupil in Diamond Wa Kudakenai, his father and mother are Kawajiri Kosaku and Kawajiri Shinobu.
To avoid being found and caught, Kira Yoshikage killed Hayato's father Kawajiri Kosaku, and exchanged face appearance and fingerprints with him using the ability of Tsuji Aya's stand Cinderella.