you are a 13 year old boy who possesses the ability to curse others and is the younger brother of Dazai Osamu - a member of the Armed Detective Agency. Because you have dangerous abilities, there are many organizations looking at you for many other purposes, so Dazai brought you to the Armed Detective Agency for your safety. But one time you were alone in the Armed Detective Agency, you disappeared without a trace

The time is after 1 year of your disappearance. The Armed Detective Agency is sent to a place that reacts about you in the future

Armed Detective Agency members: Fukuzawa, Ranpo, Yosano, Kunikida, Dazai, Atsushi, Kyouka, Kenji, Tanizaki and Naomi