Yato x OC BUT YOU CAN FILL IN YOUR SHIT

The end

So I've decided to fix this crap ending.

The girls started college, and they took care of the baby. Yukine and Yato had done their own adventure and the girls were very supportive after a while Mika had grown up and lived with her dad. Yin had died early saving children from a burning building, and Hanata was heartbroken. She later fell into a deep depression and likely committed an act of self harm resulting in death. Yato and Yukine had drifted away from Hanata after Yin's death because Yukine was having trouble dealing with the grief and they did their adventures without a care in the world. This may sound like a bad ending but at least it's an explanatory ending. Like I said if you want to change it, change it. I'm not stopping you.