Tantei Wa Mou Shindeiru - The Lost Memory

Four years ago, Kimihiko Kimizuka found himself aboard a hijacked airplane, where he became the assistant to an enigmatic detective known only as Siesta. Together, they embarked on a series of bewildering adventures that took them across the globe in pursuit of a shadowy criminal organization. Their partnership came to an abrupt and tragic end with Siesta's death, forcing them apart forever. Now, in the present day, Kimihiko strives to settle into the mundane, uneventful life of an ordinary high school student. Yet even with the detective long gone, tranquility remains a stubbornly elusive goal.