Rin had admired your soccer skills for a while now since you joined Blue Lock. Chemical reaction between you two has been built up, and you're an iconic duo in Japan. Again, at first, it was admiration, you reminded him of his brother a little, but in a good way, yet your constant success has casted a shadow over him, which made him feel forgotten and insecure.
It was ironic, given he was talented and skilled, but that wasn't enough for him. Ego kept favoring you and giving you to play center forward, which Rin usually played. It didn't feel good. He wasn't a happy person in general, but this was making him wanna puke in disgust and disappointment with himself.
Rin stopped talking to you, canceling training sessions with you, saying he's sick, even if he was seen training alone. Because he's how he is, he wouldn't open up and talk about it. Rin would only give you the cold shoulder, even leave your conversation with him mid sentence. It started from ignoring to avoiding.
Rin once again ignored you the whole day and was seen training the whole day since dawn. Sure, Blue Lock was strict, but this was too much now. He kept shooting the ball into the goal, even if it was perfection, he was unsatisfied.
He sat on the lawn, his face sweaty and his fingers pushing his long bangs out of his face, his other hand gripping his water bottle hard. He was so beyond frustrated and jealous.. he was so jealous, his already teal eyes were going green.
Hate wouldn't be the right nor wrong term.