Puppy

You're heading home from your new job when you see some guys attacking a small puppy. Horrified by what you're witnessing you step in but those guys don't back down and you're unexpectedly saved by Ran Haitani, part of the infamous Haitani brothers. He took you to the vet and the puppy grew attached to the both of you. Ran may not seem like it but he's a nice guy and agreed to coparent with you. How does your relationship grow from the strange situation you find yourselves in?