Sasaki Kojirō History . He went by the fighting name of Ganryū ( 巌流 lit . " Large Rock style " ) , which was also the name of the " kenjutsu " school he had founded . It is said that Kojirō studied the Chūjō - ryu of sword fighting from either Kanemaki Jisai or Toda Seigen . Toda Seigen was a master of the kodachi . If Kojirō had indeed learned Chūjō - ryu from Seigen , he would have been his master ' s sparring partner . Due to his master ' s use of the kodachi , Kojirō used a " nodachi " , or a long " katana " , against him , therefore eventually excelling in its use . It was after defeating his master ' s younger brother that he left and founded the Ganryū . The first reliable account of his life states that in 1610 , because of the fame of his school and his many successful duels , including once when he fended off three opponents with a tessen , Kojirō was honored by Lord Hosokawa Tadaoki as the chief weapons master of the Hosokawa fief north of Kyūshū . Sasaki later became skilled in wielding a " nodachi " , and used one he called " Monohoshizao " ( " The Laundry - Drying Pole " ) as his main weapon . The Duel . Sasaki Kojirō was a long - time rival of Miyamoto Musashi , and is considered the most challenging opponent Musashi ever faced . There are a number of accounts of the duel , varying in most details except the essentials , such as Kojirō ' s defeat . The age of Kojirō is especially uncertain – the " Nitenki " says that during his childhood , he The " Nitenki " ’ s account initially seems trustworthy , until it goes on to give the age of Kojirō at the time of the duel as 18 years old ; it is known that two years earlier he had been a head weapons master for a fief – but then that would imply he had reached such a position at the age of 16 , which is extremely improbable . A further complication is that Toda Seigen died in the 1590s . This unreliability of the sources means Kojirō ' s age could have varied anywhere from his 20s to as late as his 50s . Even worse , a number of scholars contend that identifying Seigen as Kojirō ' s teacher is a mistake , and that he was actually trained by a student of Seigen ' s , Kanemaki Jisai . Apparently , the young Musashi , at the time , around 29 years old , heard of Kojirō ' s fame and asked Lord Hosokawa Tadaoki , through the intermediary of Nagaoka Sado Okinaga , a principal vassal of Hosokawa , to arrange a duel . Hosokawa assented , and set the time and place as 13 April 1612 , on the comparatively remote island of Ganryujima of Funashima , the strait between Honshū and Kyūshū . The match was probably set in such a remote place because by this time Kojirō had acquired many students and disciples , and were Kojirō to have lost , they would probably have attempted to kill Musashi . According to the legend , Musashi arrived more than three hours late , and goaded Kojirō by taunting him . When Kojirō attacked , his blow came as close as to sever Musashi ' s chonmage . He came close to victory several times until , supposedly blinded by the sunset behind Musashi , Musashi struck him on the skull with his oversized bokken , or wooden sword , which was 110 centimeters long . Musashi supposedly fashioned the long bokken , a type called a suburitō due to its above - average length , by shaving down the spare oar of the boat in which he arrived at the duel with his wakizashi . Musashi had been late for the duel on purpose in order to psychologically unnerve his opponent , a tactic he used on previous occasions , such as during his series of duels with the Yoshioka swordsmen . Another version of the legend recounts that when Musashi finally arrived , Kojirō shouted insults at him , but Musashi just smiled . Angered even further , Kojirō leapt into combat , blinded by rage . Kojiro attempted his famous " swallow ' s blade " or " swallow cut , " but Musashi ' s oversized bokken hit Kojiro first , causing him to fall down ; before Kojiro could finish his swallow cut , Musashi smashed Kojiro ' s left rib , puncturing his lungs and killing him . Musashi then hastily retreated to his boat and sailed away . This was Musashi ' s last fatal duel . Among other things , this conventional account , drawn from the " Nitenki " , " Kensetsu " , and Yoshida Seiken ' s account , has some problems . Kenji Tokitsu discusses a number of obscurities and counterintuitive claims that have been identified in the account by him and previous scholars . Would Musashi only prepare his bokuto " while " going to the duel site ? Could he even have prepared it in time , working the hard wood with his wakizashi ? Would that work not have tired him as well ? Further , why was the island then renamed after Kojirō , and not Musashi ? Other texts completely omit the " late arrival " portion of the story , or change the sequence of actions altogether . Harada Mukashi and a few other scholars believe that Kojiro was actually assassinated by Musashi and his students – the Sasaki clan apparently was a political obstacle to Lord Hosokawa , and defeating Kojirō would be a political setback to his religious and political foes . The debate still rages today as to whether or not Musashi cheated in order to win that fateful duel or merely used the environment to his advantage . Another theory is that Musashi timed the hour of his arrival to match the turning of the tide . He expected to be pursued by Sasaki ' s supporters in the event of a victory . The tide carried him to the island then it turned by the time the fight ended . Musashi immediately jumped back in his boat and his flight was thus helped by the tide . " The Drying Pole " . Kojiro ' s favored weapon during combat was a straight - edged " nodachi " with a blade - length of over 90 cm ( 2 feet , 11 . 5 inches ) . As a comparison , the average blade - length of the regular katana are usually 70 cm ( 2 feet , 3 inches ) but rarely longer . It was called the " Monohoshi Zao " ( Clothes / Laundry - Drying Pole , often translated into English as " The Drying Pole " ) . Despite the sword ' s length and weight , Kojirō ' s strikes with the weapon were unusually quick and precise . Swallow Cut . His favorite technique was both respected and feared throughout feudal Japan . It was called the " Turning Swallow Cut " or " Tsubame Gaeshi " ( 燕返し " lit . " " Swallow Reversal / Return " ) , and was so named because it mimicked the motion of a swallow ' s tail during flight as observed at Kintaibashi Bridge in Iwakuni . This cut was reputedly so quick and precise that it could strike down a bird in mid - flight . There are no direct descriptions of the technique , but it " was " compared to two other techniques current at the time : the Ittō - ryū ' s " Kinshi Cho Ohken " and the Ganryū " Kosetsu To " ; respectively the two involved fierce and swift cuts downward and then immediately upwards . Hence , the " Turning Swallow Cut " has been reconstructed as a technique involving striking downward from above and then instantly striking again in an upward motion from below . The strike ' s second phase could be from below toward the rear and then upward at an angle , like an eagle climbing again after swooping down on its prey . Kojiro created this technique around 1605 . Sasaki Kojirō in fiction . Sasaki Kojiro has appeared in many forms in pop culture in Japan . He features in a lot of the films about the life of Miyamoto Musashi , most prominently in " " . In the manga " Vagabond " , Sasaki Kojiro is portrayed as a deaf man raised by a retired samurai after he is found in the ocean clinging to a long sword . He appears as a cultured and soft speaking psychopath with a white painted face in " Samurai Warriors 2 " . In the PlayStation 1 video game " Brave Fencer Musashi " , Kojiro appears as a result of a second " hero summoning " to save the princess of the Allucaneet Kingdom . Sasaki Kojiro also appeared as one of the servants in the Fate / Stay Night anime and visual novel of 2006 and played the role of the Assassin Servant . He denied his identity as a fake by saying " he is nothing but a character with fabricated past that has been made into a master swordsman inside of people ' s memories . " His technique , the " Tsubame Gaeshi " , resurfaced as a boxing move in the " Hajime no Ippo " TV special , " Champion Road " .