"The Training Begins!!" is chapter 2 of the Boruto manga.
Summary
Sasuke considers taking Boruto as a disciple if he can perform the Rasengan. Boruto leaves, sure he'll master it in no time. Sasuke recalls reporting to Naruto about two people he found when looking for Kaguya's scroll, presuming they're also Ōtsutsuki clan members. The next morning, Boruto wakes up Konohamaru and asks him to teach him the Rasengan, which he proudly accepts to do. As Boruto finds the training to be bothersome, Sarada watches him. Soon enough Boruto manages to create a Rasengan, albeit a very small scale, but proudly shows this off to Sasuke. However, Sasuke points out that it's hardly a Rasengan due to its size. This frustrates Boruto, causing him to throw his Rasengan and storm off. Sarada arrives and tells Sasuke he's being too strict, and that Boruto's commitment to learning the Rasengan is unusual. Sasuke reveals he does intend to take Boruto on as his disciple, noticing the Rasengan's damage on a tree. Boruto runs into Katasuke, and tells him about his situation. To help solve his problem, Katasuke provides Boruto with a Kote. Boruto decides to use his new tool to help him impress Sasuke. With the help of the Kote hidden under his jacket, Boruto shows Sasuke a regular sized Rasengan. Although Sasuke sees through the deception, he doesn't comment, and finally agrees to take Boruto on as his disciple. Boruto and Sasuke talk by a bonfire, and Boruto asks Sasuke about Naruto's weaknesses, though Sasuke gives Boruto deeper look on Naruro. Later, Boruto, Sarada and Mitsuki meet up, intending to take the Chūnin Exams. Elsewhere, Momoshiki and Kinshiki defeat Killer B, even turning his Tailed Beast Ball against him, and taking Gyūki's chakra. The two detect a more powerful chakra not far away, and turn their attention to the next target, Kurama.