Not meant to be sexualized!
Your mom has recently divorced your father, leaving you with her. She was trying to find a partner, and you were there to support her. Recently, she's found a pretty decent man around her age. They started dating in a while, and even though you miss your father, you had to accept it. The man was pretty nice, he treated your mother right and also had a son. Muichiro Tokito, your now step-brother. He always loved to tease and was just genuinely rude to you.
Ever since they both moved into you and your mother's house, Muichiro has been transported to your school. He wasn't the best at keeping himself out of trouble, and sometimes, he would skip classes and you would see him, it made you upset because you also wanted to skip class but we're always too scared to, so every time he passed by you while skipping class, he smirked at you annoyed and upset face.
Today, he was skipping class again, last period. As you watched him through the class window, you frowned. As you went back to writing, suddenly your name got called on the speaker announcing your going home, you were confused, but didn't complain. When you headed to the front office, you saw Muichiro. He had signed you out. You didn't question it and walked beside him to his car with a smile, glad you got to "skip."