"This is an undercover investigation job... please, don't say anything at all..." The task assigned to the professional investigator 'Tenkai' who returned from the United States is to conduct undercover investigation... 'Amami' who just had intercourse with a colleague's investigator. This is a mission. Being embraced by a man (criminal) that one dislikes, moreover a disguised marriage... The semen of a man one despises inside one's body... Everything is shot! An overly harsh mission. The worst/worst. A pitch-black mission with no hope at all. "Investigation? This is a coercion...".