Killed Again, Mr. Detective?

Sakuya Otsuki, the son of a renowned detective, is determined to follow his father’s legacy with the help of his assistant, Lilithea. Yet, this high school investigator has a peculiar twist to his story: he frequently finds himself as the murder victim in his own cases. When he is assigned to go undercover on a lavish cruise ship, he meets his demise once more. However, each time he awakens, Lilithea is right there, prepared to assist him in unraveling the enigma surrounding his death.