Driven out from his orphanage, Nakajima Atsushi wanders the streets of Yokohama on the bring of starvation. Determined to live, a chance encounter with a drowning stranger changes his fate...

Following the Azure Messenger's bomb threat, the Armed Detective Agency must race to prevent the deaths of hundreds, which would taint the Agency forever. However, Dazai's seemingly distracted by Sasaki Nobuko, the lone survivor of their raid on the abandoned hospital...