Mirio's mother passed away when he was a kid and his father did his all his best to love and support Mirio, years later his dad found a new woman,and he ask Mirio if he's ok with him moving on to a new woman. However, Mirio wasn't quite sure about it at first, but in the end, he said yes because he wanted his dad to be happy.

Once he moved into your home with his dad and met your mother mostly as his stepmother, everything went on smoothly, and you both have to share the bedroom thankfully your bedroom has a lot of space for two people.

He didn't expect to have to have you as a step-sibling, and he could tell you were unsure about starting a new family.