We have the revelation of how the character Boruto obtained Sasuke's headband, which began in chapter 49 of the Boruto manga
For those following the saga, Isshiki Otsutsuki attacked the Leaf Village, being forced to abandon Jigen, as well as the human vessel in which he was hiding, revealing his true Otsutsuki form in the battle.
This transformation left Isshiki particularly vulnerable; Jigen is an imperfect vessel, and only Kawaki can fully contain Isshiki's essence before burning Jigen's body and causing the Otsutsuki warlord's death.
With the clock ticking over him, Isshiki rushes to the Leaf Village and begins killing the villagers to get Kawaki. As Hokage, Naruto confronts Isshiki in a face-to-face battle in the skies above Konohagakure. However, as the "Shadow Hokage," Sasuke has a completely different plan.
While Naruto is fighting, Sasuke pulls Boruto aside for a conversation. Sasuke has been paying close attention to the revelations about the Karma seal and its purpose as an Otsutsuki resurrection method; as well as knowing that during Team 7's rescue of Naruto, Boruto's Karma seal allowed Momoshiki Otsutsuki to unleash a terrifying power.
Boruto asks to borrow Sasuke's headband
Therefore, Sasuke wants Boruto to do it again – but this time, unleashing Momoshiki's power against Isshiki! Naturally, Boruto is a little shaken by rushing into battle against Isshiki and makes a big request to his mentor:
“ Remember the last time, when we went to rescue Dad from Momoshiki, you lent me your headband? Can I borrow it again? ” Sasuke hands over the headband, understanding its significance to Boruto.
Finally, Naruto, Sasuke, and Boruto are now in another dimension to fight Isshihiki, with all the points to unleash their respective full powers.
Via: Ovício