Shun is a third generation descendant of a Japanese orphan left behind in China during World War II. Takeru is a lonely and reckless young man whose family was murdered when he was a child. Shun, Takeru and Kasumi, who has an equally troubled past and background, become collaborators after being hired by Kuchinawa in a police undercover operation to take on a drug cartel in a Chinatown. The drama follows their ability to work together and grow individually.

《四重奏》根据直木奖获奖作家大泽在昌的最新作品改编，讲述个性不同的三个年轻人潜入犯罪团伙搜查，相互信任并一起成长的故事。福田沙纪过去扮演的多是清纯少女，这次角色和以往不同，是一个全身纹身的强悍角色，她为了这个角色正在努力学习，她说：“这是一个我从未接触过的世界，角色也是从未挑战过的，非常期待呢。”

저마다 개성이 다른 젊은이 3명이 범죄 집단에 잠입 수사를 펼치는 과정에서 서로를 믿으며 성장하는 이야기를 그린 드라마