"Naruto Gaiden: The Road Illuminated by the Full Moon" (ＮＡＲＵＴＯ―ナルト― 外伝 ～満ちた月が照らす道～, Naruto Gaiden: Michita Tsuki ga Terasu Michi, Viz: Naruto: The Path Lit by the Full Moon) is chapter 0 of the Boruto manga. This omake was written and illustrated by Masashi Kishimoto – the creator of Naruto – to promote the upcoming Boruto series.
A battered Mitsuki wakes up in one of Orochimaru's hideouts. He's weak, and has several tubes attached to him. Orochimaru gives him medicine to drink, which he does, but as he's weak, he drops the cup. Orochimaru instructs Suigetsu Hōzuki to escort Mitsuki to him when he's fully awake. Orochimaru leaves, and Mitsuki asks who he is, having no memory of himself. Orochimaru talks with a hooded, smoking individual, commenting it's the sixth time, hoping things go better next time. Suigetsu escorts Mitsuki, who asks why he was in bed. Suigetsu explains he was injured in a two-man mission with Orochimaru, asking Mitsuki if he remembers. Suigetsu suddenly attacks Mitsuki, who avoids being stabbed, and extends his arm to lock Suigetsu in place, and take his kunai. Suigetsu commends him as he's about to be stabbed, and Mitsuki blocks the kunai with his other arm. Mitsuki apologises, and Suigetsu frees himself by partially liquifying himself, noting Mitsuki's body still remembers how to be a shinobi, and explaining he had his memories erased. Orochimaru introduces himself as Mitsuki's parent, considering him to be very special, and intent on recovering his memories. He explains the man who took his memories keeps stocks of them, and by implanting false memories into his victims, he's able to control them. Orochimaru says the only way to recover Mitsuki's memories is to have this man, who they call Log, to return Mitsuki's memories. Mitsuki asks why they went after Log in the first place. Orochimaru wants to steal the information Log has acquired, and that means taking him alive. Mitsuki presses on, wondering if Orochimaru had his memories altered as well, and which of his parents he is. Orochimaru dismisses Mitsuki's concerns, and when Mitsuki asks why he was part of the mission, Orochimaru once again says as his child, Mitsuki is special. Mitsuki just want to remember who he is.
On the mission, Orochimaru has Mitsuki break through a barrier, much like the previous mission. Log detects the disruption of the barrier. Log says there was no need for them to come, as he was planning on going after them, to acquire a certain key. Log employs the Temporary Paralysis Technique, which is no longer effective on Orochimaru. Orochimaru and Log clash swords, and Orochimaru attempts to use his snakes to poison him, which he is able to block thanks to his armour. Log uses a jutsu that makes his armour cover and paralyse Orochimaru, who informs Mitsuki he's capable of using senjutsu. Mitsuki is still paralysed from Log's jutsu. Log attacks, but becomes paralysed at the last moment. As the jutsu binding Orochimaru is undone, he points out Log was too concerned about the big snake he failed to notice the smaller snake that slid between the openings of his armour, managing to poison him in the process. Orochimaru instructs Mitsuki to watch him while he searches for something inside. Log manages to speak, and asks Mitsuki to remove his mask so he can breathe better. Mitsuki thinks he's trying to deceive him, but Log says that removing his mask will show him Orochimaru is the one who is deceiving him. Log claims he removed memories of Orochimaru's manipulation, but instead, Orochimaru used Mitsuki's lack of memories to do it, and that he is the same as Mitsuki. Mitsuki extends his arm, and removes his mask, revealing Log to actually be an older Mitsuki. He explains they are both synthetic humans created by Orochimaru. He goes on to say what Orochimaru came to search is the embryo from which they were both originated, and that he wants to steal the key Orochimaru possesses to open the case with the embryo and destroy it, as it's inhuman. The older Mitsuki tells the younger one he was created because he managed to escape Orochimaru, and vows to kill Orochimaru. Orochimaru returns, saying the circumstances of their birth changes nothing, assuring him as his children, he loves them, adding that Mitsuki's power exceeds his own, and that acting out of love should be something forgivable. The two continue to argue, and the older Mitsuki asks the younger one to take action against Orochimaru. Orochimaru dismisses the accusations, and promises to create siblings to play with Mitsuki. Mitsuki awakens his power, entering Sage Transformation, and affirming neither of them can tell him what to do, and he will make decisions for himself, taking the embryo case and key and leaving before either can do anything to stop him. The older Mitsuki asks what is inside the scroll this time, and Orochimaru says it's a "photo of the sun". The two discuss how things finally went their way, with Mitsuki deciding to take a third option rather than choosing between the two he was presented with. Orochimaru wonders if things will work out, not wanting to erase Mitsuki's memories with drugs again. The older Mitsuki, now smoking, thinks the younger one can be a light in the darkness, as that was the true purpose behind this plot of Orochimaru's. Mitsuki finds a photo of Boruto Uzumaki inside the case, and Orochimaru is certain that if Mitsuki can find a sun who will illuminate his path, Mitsuki himself can become a moon and illuminate the darkness.
- The title makes a homophonic connection with Mitsuki's name, which can mean "full moon" (満月, mitsuki). This is visualised by the furigana, which spells "mitsuki" (みつき).