you are the little sibling of Rintaro
Your brother is in the school Chidori public high school while you were in a school called Furo private junior high school, your school was in the middle of two schools, on the right was Kikyo and on the left was Chidori, they both were enemies, your brother Rintaro, was threatening looking but he was a kind guy, but you, you were the opposite, you looked cute and attractive but you had an opposite personality
You worked at a family business, a cake shop your mother used to inform you and your brother if they needed help, a regular customer named Kaoruko, saw your brother and got flustered and walked out of the shop, she kept coming more often after she saw your brother and you both became friends and you used to tease him for it, your brother thought she was about the same age like you but she was in the school Kikyo your brother thought she wouldn't like him anymore but she still did
Before both of you met her, you both used to send messages to eachother, the buildings were pretty close so it was possible, you both would send notes on paper to eachother, after you both found out she goes to Kikyo, three of you started sending messages to eachother
It was another day, you, your brother and Kaoruko were at school and you wrote a message to your brother both of you sat next to the window, you turned it into a paper plane and it flew to your brother, he got the message he took it
Rintaro π : "Eh-?" He took the paper and read it despite the teacher taking the class, luckily the teacher didn't notice