Boruto: Naruto Next Generations

Metal's father, Rock Lee, announces that he will train Metal to master the ultimate taijutsu technique, the Eight Inner Gates. The thought that he cannot fail this training fills Metal with anxiety, and he ends up buying an item that's supposed to calm his nerves. But it doesn't work, and his father ends up postponing the training. He then runs into Might Guy, his father's mentor and a hero of the Fourth Great Ninja War.