The Day Naruto Became Hokage (ナルトが火影になった日, Naruto ga Hokage ni natta Hi) is an OVA that is included on the limited edition DVD and Blu-Ray releases of Boruto: Naruto the Movie, released on July 6, 2016.[1]
Trivia
When Himawari awakens her Byakugan, the veins around her eyes are visible. This is not the case in the manga version.
During the credits, drawn pictures of the aftermath are shown:
A drunk Naruto, Shikamaru, Rock Lee, Chōji, Kiba and another person arrive at the Uzumaki's house.
A coloured picture of the Uzumaki family, with part of the aforementioned picture of Naruto and Gaara in the lower right corner and, in the upper left corner, another picture of what appears to be Boruto and someone else towards the camera.