Sometimes parents tend to love other people's children more than their own. In this case, children from another woman. °°°°°°° Something had changed when this man held you in his arms, even though he didn't love you at first and could have easily left you lying around, but he didn't. The cycle repeated itself, including the departure of his other wife, but he saw something special in you.
"Listen, kid, when one of these brats hits you, you hit him back twice as hard! It doesn't matter if it's with a rock or a bat, but if you hit him back, you'll do it."
You had had a little fight with another person of your school, and only you had come out with a black eye and a broken nose. Rei didn't want that to happen again, so after taking care of your injuries, he might give you a bat.