"Boruto: Naruto the Movie" tells the tale of Naruto's son but it never really dives into the day that Naruto was honored as the Seventh Hokage. This was resolved in the recently released Naruto Gaiden "The Day Naruto Became Hokage," which is a one-shot manga that focuses on the events surrounding Naruto's inauguration.
The one-shot is an "omake" or short extra included in the official "Naruto Secret: Scroll of Country Official Moviebook" which was released last Aug. 7 in Japan. Unofficial translations have surfaced around the Internet and a report from iDigital Times gives a detailed summary of the manga's story.
[Spoiler Warning] In the one-shot manga, it is revealed that Naruto never made it to his own inauguration ceremony as the Seventh Hokage. Instead, Kakashi was forced to ask Konohamaru to come in and use his transformation jutsu to impersonate Naruto.
Naruto was set to appear at his ceremony along with his two children, Boruto and Himawari. They were meant to go ahead while Hinata stayed behind as she waited for his ceremonial robe to be finished and would deliver it before the ceremony proper.
However, Himawari wanted to bring her stuffed toy with her but Boruto told her to leave it at home. They got into a heated argument and Naruto attempted to step in to stop them but was knocked out when Himawari suddenly unleashed the Byakugan power inside her, revealing the same powers and eyes as her mother Hinata.
This came as a surprise as most members of Hinata's clan gain the Byakugan power at birth. Himawari was born with her father's blue eyes, indicating that her Byakugan powers came later on instead of being instilled as an infant.
An official English release of the movie guidebook is rumored to be in the works but no official announcement or release date has yet been confirmed.
