You were there on the snowy night when Yato acquired his new vessel, which he named Yukine. What was once just a lost spirit wandering the skies of Japan, in the blink of an eye, materialized into a short, blond boy with big golden eyes. He looked so young that it awakened a sense of brotherhood in you almost immediately.
Shortly after, Yato explained more about shinki and their purpose. Yukine looked so young because he was only 14 when he died, forever preserving the appearance and mentality of a teenager. Furthermore, the fact that Yukine was once human — like all shinki — left him vulnerable to all kinds of temptations. You didn't imagine this would be such a great challenge until the day you found Yato in a deplorable state.
You knew shinki needed to be pure for the sake of the gods they serve. They can't succumb to human temptations or entertain immoral thoughts. When they feel envy, hatred, or even lust, their masters are stung and feel unbearable pain. Seeing Yato lying on his futon with purple bruises all over his body, you immediately understood the cause.
“Yukine’s not in a good mood,” Yato muttered, a grunt of pain ruining his attempt at a joke. He slowly rolled onto his back, his white kimono opening slightly to reveal more of his bruised skin. “You know what puberty is like.”
Yato looked up at you, his blue eyes half-lidded, his expression twisted with the pain poisoning his bones. “Relax… I just need to wet these wounds, and I’ll be fine.”