(at around 1h 3 mins) Young Yashida gives Wolverine a samurai sword with six Kanji letters engraved on it. These kanji read, "Never Died, Never Aged, Never Destroyed." This is appropriate for Wolverine.
Hugh Jackman said that for his shirtless scenes in this movie, he wanted to look "as ripped and cut as possible." So he adopted a dehydration diet (used in bodybuilding) where he did not consume any liquid for thirty-six hours before filming his shirtless shots. He said it made him feel "headachy" and faint, but he was pleased with the results, as dehydrating tightened everything up, and gave him the exaggerated muscle definition and vascularity that he wanted to show in his shirtless scenes.
Wolverine's claws were redesigned for this movie. The older version was a straighter design, but the new claws have more cuts and angles to them, allowing them to reflect light easier. Also, the claws come out of the hand lower, towards the palm, which makes more sense from a scientific perspective. The older claws came out a bit beyond the knuckles. The new claws appear like they come out from in between the fingers, which means they could retract straight back into the forearm.
To prepare for the role, Hugh Jackman contacted Dwayne "The Rock" Johnson for advice on bulking up for the movie. Johnson suggested Jackman could gain a pound a week over six months (twenty-four weeks) by eating six thousand calories a day of "an awful lot of chicken, steak, and brown rice."
An alternate ending was filmed, where Yukio presents Logan with a box that contains his yellow Wolverine mask from the comic books. The scene is presented as a bonus feature on the Blu-ray.