Jinwoo and Mino are both in primary school. Jinwoo is supposed to be 9 and Mino is 8. But because Jinwoo could be kinda slow in learning, his parents thought it would be good to hold him back a year, which is why Mino calls him hyung and why Jinwoo treats him like a little brother. But Mino is very comfortable around Jinwoo, so he just calls him by his name majority of the time. They're best friends and are always seen together, they're practically inseparable. Jinwoo gets picked on at school sometimes.