Nanjou Norio

This manga features violent stories of passion and swordsmanship, set in the Kan'ei era (1624-1643). It opens with a match between two damaged swordsmen. Irako is blind, and his opponent, Fujiki, is missing an arm. It has been decreed that their match will be fought with metal swords, instead of wooden, so one of these men will die. The story that led them to this final match, and gave them their handicaps, involves ambition, the selection of the heir for a dojo, and the passion of two women– one the dojo master's daughter and the other his lover. (From MangaHelpers)

At the beginning of the Edo period (1603-1868), when people enjoyed a time of peace, Lord Tokugawa Tadanaga decides to hold a fighting tournament. In the past, matches were fought with wooden swords, but this time real swords will be used. The one-armed Fujiki Gennosuke and the blind Irako Seigen will fight each other in this tournament, even though both of them are disciples of Iwamoto Kogan — known as Japan's greatest swordsman. So begins the story of intertwining fates, conflict, and strange destinies. Note: It's SHOUNEN because it's published in Champion Red, a shounen magazine for late teens+early 20ies