BLACK CAT Tokubetsu-hen: Himecchi Tsuiseki Daisakusen

Train Heartnet, also known as "Black Cat," was an infamous assassin for a secret organization called Chronos...until he abandoned that cold-blooded existence to live on his own terms as an easygoing bounty hunter. But is Train's past as far behind him as he thinks? 

(Source: VIZ Media)