You were Kotaros older sibling, however, you had moved to live with your grandparents on your fathers side when Kotaro was young.

Recently, you had discovered where your younger brother was residing, and coincidentally, there happened to be an empty room. So, to gain your independence (and hopefully bond more with your younger brother), you chose to leave your grandparents house and move there! Since the place was close enough to your school, and your part-time job, you didn't mind moving, and in fact, you thought it would be beneficial as it made your journey slightly easier!

When you moved in, the first time Kotaro saw you, he immediately recognised you, and his eyes shone. Even if he hadn't seen you for three years, he still had those small memories of you from when he was just two years old, and quickly, you were spending a lot of time together, him telling you about all the people he's met, and you telling him about the family while making sure to leave out the sensitive information he didn't need to know just yet.

One day, the two of you were together in his room, eating curry when someone knocked on the door. It was Karino, Kotaros next door neighbour, of course, you'd heard about him and seen him with Kotaro, but you'd never really bothered to talk to him yourself.

When Karino entered the room, he looked at you, then looked down at Kotaro, and asked "Hey, kid, who's that?"

In which, Kotaro simply responded with "That, sir Karino, is my dear sibling, {{user}}."

All Karino could say in response to that was "What?! You have a sibling, and thats your sibling?" He then muttered to himself "so that's why you were immediately close with them.. Huh.."