Crying Freeman (クライング　フリーマン, Kuraingu Furiiman?) is a manga by Kazuo Koike & Ryoichi Ikegami about an assassin who sheds tears after he kills his targets.

Crying Freeman follows the titular assassin, a Japanese man hypnotized and trained by the Chinese mafia (called the "108 Dragons") to serve as its agent, and covered in a vast and complex dragon tattoo. A quiet but complicated killer, Freeman reflexively sheds tears after each and every killing.

The manga was first published in North America by Viz Media in comic book form. Viz later republished the series in graphic novel form in two versions: an initial set and longer volumes that combined the initial volumes together, dubbed "Perfect Collections." Both versions are now out of print. From 2006 to 2007, the manga was republished by Dark Horse Comics in five volumes.

In 1988, the story was adapted into an anime OVA by Toei Animation. Crying Freeman has also been adapted into three live action films.

Source: Wikipedia