So, those are Yukine's memories that Yato learn when he meets Yukine for the first time. We can see that his mother and sister leave for a journey maybe, with not a lot of bags so it should have been a fast trip or maybe a forever leave. Yukine should have stayed with his father who, after his wife's left, could have become an alchol dependent (those empty bottles) and he could have lost all of his money (the empty pocket). Yukine maybe wrote some letters to her sister (that could explain his good calligraphy as Hiyori herself said) His father could have found out it (the shoes on the letters) and he could have killed the poor angel Yukine. When Yato learns those memories, he cries. Maybe it is due to the similar story Yato himself has.














