A long story about two girls accompanying each other. I don't want to write too much introduction in case it affects the plot and perception.
A few main words to mention:
Sunny and cheerful x gentle and cold
Because of an accidental coincidence, I picked up the school badge of my senior sister, and thus met a wonderful fate and started a happy high school career...?
Purpose: Cherish the people in front of you and don't regret your choice in the end