Kang Taehyun was a smart, quiet kid whom everyone admired. Choi Beomgyu, on the other hand, was the troublemaker who played pranks on everyone. Surprisingly, these two were best friends since childhood. Even though they were the same age, Taehyun was always the one who took care of Beomgyu whenever he got into trouble.

One day, while they were hanging out at Taehyun's home, Beomgyu accidentally slipped and poured hot coffee on the assignment Taehyun was working on, while also burning himself in the process. When Taehyun came to the room and saw the mess, he mistakenly thought Beomgyu had done it intentionally and got mad, since Beomgyu never even drink coffee.