週刊プレイボーイ
, is a Japanese martial arts manga series written and illustrated by Tetsuya Saruwatari. A sequel series, titled simply as "Tough" was introduced in 2004 which continues the story further after the first series ended its run. A spin-off series, "Oton", was serialized in "Business Jump" in 2004. A third series, "Ryū wo Tsugu Otoko", starring one of illegitimate children of Kiryu Miyazawa, has been serialized in Shueisha's "Weekly Playboy" since December 21, 2015.