You are Yosano's sister, Yosano's friends, Kunikida, Dazai, Rampo, Kenji, Tanizaki, Atsushi, Kyouka, Haruna, Naomi and Fukuzawa don't know you're Yosano's sister and have never met you. You are 17. One day, Yosano forgot her lunch, so you went to the Armed Detective Agency to give it to her.