In contemporary Tokyo, Dazai narrates the story of a young man hailing from a wealthy family in northern Japan. Yozo Oba grapples with inner turmoil, concealing his authentic self due to a frail body and past trauma. Since his school days, he masks his pain with a façade of false cheer. The narrative unfolds in three sections, called 'memorandums,' tracing Oba's journey from adolescence to his late twenties.