Kenshin is a Japanese prince who does not like war. He appears in the film Teenage Mutant Ninja Turtles III. As he was growing up his mother died and he only lived with his father Lord Norinaga and the royal guards. During the time as he was growing up he had fallen in love with a girl named Mitsu and after his mother died his father did not like Mitsu so every time that Kenshin would try to leave the palace in order to go see his love Mitsu, his father would send the four Honor Guards after him.
After several times of him being chased after when he would leave he found out that his father hated Mitsu so much that he was planning to attack her and the people of her village. When Kenshin heard that news he tried one last time to go to her and help her but the Honor Guards captured him again and when they did and were taking him back to the palace he yelled her name. Then when he was returned to the palace his father was about to come down hard on him when Walker the English gun salesman showed up. Then as Kenshin walked back inside the palace he went into the temple and caused the four priests to leave. He then found the magic Septer and caused it to activate making him swap places in time with April O'Neil who was in modern day New York City inside the new home of the Teenage Mutant Ninja Turtles. After the switch happened and Kenshin looked up and saw the four turtles and Splinter he fainted. Then after he came to Splinter talked with him and Kenshin told the turtles about what caused him to come there. After Casey Jones was brought down to the turtles' home he stayed with Splinter while the four turtles activated the septer and went back in time to save April. When the turtles disappeared Kenshin was shocked to see it was his father's four Honor Guards who came in their place. During the time the turtles and April were in Japan, Casey Jones and Splinter did things to keep Kenshin and the Honor Guards occupied. Casey turned on the TV and all five of the men from Japan watched a Hockey Game.
After the Hockey game was over Kenshin watched as Casey was trying to teach the four Honor Guards how to play Hockey but the four men thought that hockey was played by beating each other up because of what they saw members of the two teams on TV do to each other. After a while Kenshin saw a poster in the turtles home that shows a man holding a woman a certain way and kissing her. At that same time Casey had taken the four Honor Guards up into the city above to a certain bar and grill. Then as the time got closer to the end of the 60 hour time that the four turtles told Kenshin that they had to be able to get things back to normal he was getting impatient. He got tired of waiting for the turtles to come back and when Casey was getting the four Honor Guards to come back from the bar Kenshin had activated the septer and was wanting to go back to his time because he was so worried about Mitsu. Then when Kenshin and the Honor Guards were sent back to their time and the Turtles and April were back in their home it showed then back in Japan that Lord Norinaga was shocked to see his son again. Then when his son handed Mitsu the golden Septer and then Mitsu handed the septer to Lord Norinaga who was down on his knees he then looks up and his Honor Guards walk by him with only the special diapers that they wore under their armor on. Then after Norinaga got up and walked past his son to put the septer back in its proper place Kenshin then grabs Mitsu and kisses her with her in the position matching the poster he saw on the wall in the turtle's home. So it is believed that right there the two families made peace and as a result Kenshin and Mitsu got married to where there would be no more wars between the two families.