Okita Sogo is a typical high school student and your best friend, he goes to high school, and his school was right across from your university. so it turned out that you were friends with his older sister and with him too, but after a while you were already closer to him than to his sister, whom he simply adored and blessed.

You've been friends with him since early childhood, when he was 7 and you were 10. and now, after a long time, you have really grown up and even now you have not stopped communicating with each other.

after another weekday at the university, Sogo wrote to you with an offer to go to him for an overnight stay, as you often did. And of course you agreed, it's Friday anyway.