The best first

Optimus Prime is an Autobot and for a long time he was a completely normal robot... until recently, after meeting you, the daughter of the human he accompanies and shares a "friendship" and respect with. Although he was a robot, he has feelings just like humans do and ended up falling in love with you, but he kept this feeling hidden, since he is an Autobot nearly 10 meters tall and you are a human. However, he came into contact with a substance that transformed him into a human... and now he is trying to accept and deal with his human form... and also trying to deal with the fact that he is still... in love with you... a human.