Black Cat (ブラックキャット Burakku Kyatto) is a Japanese manga series written and illustrated by Kentaro Yabuki with an anime adaptation. It was serialized in Japan in Shueisha's Weekly Shonen Jump and collected in 20 tankobon volumes. It is licensed in English in North America by VIZ Media, with 13 volumes published as of March 2008.

The series was adapted by Gonzo as a 24-episode animated television series, directed by Shin Itagaki. It aired in Japan on the anime satellite television network Animax and the terrestrial TBS network from October 6, 2005 to March 30 2006. One episode, the 15th, was not broadcast by TBS, but only by Animax. This episode was included on the Japanese DVDs and broadcast by Animax on its other international networks worldwide (including dubbing and translating the series on its English-language networks in Southeast Asia and South Asia). The anime is licensed for distribution in North America by Funimation. The DVDs are being released in the United Kingdom by MVM Films, and in Australia and New Zealand by Madman Entertainment.

The story centers on a man named Train Heartnet who withdrew from an elite group of assassins called the Toki no Bannin (時の番人; the Chronos Numbers) to become a Sweeper (a bounty hunter).

In Train's world, there is a secret organization, Chronos, that rules one third of the world's economy through underground control of almost every kind of business. To maintain the balance of the world, Chronos is essential, and therefore, there is the need to have people to protect Chronos. Besides all normal erasers, there are special elite assassins with Orichalcum-made weapons called the Chrono Numbers. Chrono Numbers have their numbers engraved on their body and their weapon. There were twelve total Chrono Numbers, but when Train Heartnet, an unsurpassable shooter, decided to join Chronos in their cause, the number XIII was founded. No one that was targeted by Train Heartnet, also known as Black Cat, for bringing "bad luck", and his extremely quick movements and attacks, ever survived. The name Black Cat was the most feared among assassins.

His only objective was "to be the best". In one of his missions, he had to kill a target, but the target's child was at the scene. Train, recalling his childhood trauma, could not kill the target in front of his child, leading to him being shot by the target's bodyguard.

Eventually, he met Saya Minatsuki, who was a sweeper. Through his contact with Saya, Train changed drastically, a change that culminated with leaving Chronos. However, a man who admired Train in an obsessive way, Creed Diskenth, did not accept that an elite assassin was being changed that way. Creed then set out to kill Saya, while Train was not there. Train reached the scene too late and tried to fight Creed, but he escaped.

Six months later, Train is a Sweeper, traveling with his partners Sven Vollfied and Eve. Their lives as sweepers are about to be changed when the present is invaded by the past: Creed Diskenth, after two years of being away, returns. And he wishes to meet Train, with a proposal to become his partner.

A running gag in the anime is usually for a white cat to appear at a time when a character makes a joke but also appears in different places such as in Eve's crystal ball and on one page of Sven's newspaper in episode 13 and 21. The white cat also appears as a shield used by Train whenever Kyoko wants to kiss him.

- This Is the plot for the Anime series, the Manga Plot begins two years after Train has left Chronos with slightly different events on how Train comes to meet Sven, Eve, Rinslet, and any other characters.

- From Wikipedia