Sister.. I like you

Episode 1

“I like you, noona.” Jimin, a junior I’ve known for a long time, whispered to me. I started to feel excited for Jimin, who I usually couldn’t feel anything for.But, our school doesn't allow dating, so I had no choice but to tell Jimin, "Jimin, you know our school doesn't allow dating, right?" Jimin said, "I know, haha. It's a really shitty school, lol. I just like you, noona."
The next day
Jimin took care of me more than usual. He used to just joke around, but maybe it's because I confessed to him and he accepted?