In Nami no Kuni,Team Seven was on a mission to protect a bridge builder named Tazuna. Sasuke was fighting the Ice style user, Haku and was in a standstill until Haku used her Crystal Ice Mirrors. After Melding herself in the countless mirrors her speed was proven too much as Sasukewas stabbed and cut by senbon countless times when Naruto arrived saying, "Sorry I'm late, but I'm here to help."
Seeing as he was about to get showered with senbon by Haku, Sasuke pulled a substitution jutsu replacing himself with Naruto at the last second as he says, "Thank You Dobe, you were a great human shield for me."
"Well Done Sasuke. You put an end to the demon that took Minato-Sensei and Kushina-sama away from us." Kakashi said as he held a pitiful grudge towards Naruto for his birth causing the death of his sensei and Naruto's father Minato Namikaze.
Sakura was horrified. "How could Sasuke-kun do such a thing to Naruto? No Naruto-kun was right, Sasuke is a teme and Kakashi-sensei is supportive of it. He's the one lower than trash and I need to report this to the hokage when we get back."
But kakashi caught on to her, and knocked her out by punching her in the stomach and tossed her and Naruto's body off the bridge. He then looked at Tazuna who was speechless "Tazuna, If you care about your family not to tell anyone what happened."
Sasuke and Kakashi believed they got away with it only to get knocked from behind by Zabuza who hit him with the blunt side of his Kubikiribōchō and an anbu with a white snake mask by using her own senbon.
The Anbu looked at Tazuna and Zabuza and said, " Don't worry. I saw everything. Was tailing them as Sandaime-sama knew the scarecrow had it in for the blonde and the duckass is a power hungry idiot. They will answer for their crimes. My fellow Anbu took care of Gato and his men. Zabuza, you and your accomplice will come with me for questioning and then we would like you both to join Konoha on behalf of our Hokage." Zabuza nodded and followed the masked woman with Haku tying up Sasuke and Kakashi.
A few hours later Sakura and Naruto, who are unconscious, are washed on the shore on an island of ruins where a woman wearing a nuns habit and has a bird like symbol on her forehead spots the two "At last, Lelouch's heir has found." She then takes them to rest and heal in a temple that has the same symbol.
The next day, Naruto awakens on a bed with bandages wrapped around his neck, arms, and shirtless chest and stomach. Seeing Sakura next to him, his mind wondering what this place is as the pink haired kunoichi awakens. Upon seeing her blonde teammate, Sakura immediately started to cry. "Naruto-kun you are alive. When Sasuke-teme replaced himself with you. I feared for the worst."
Sakura explained the events to him after he lost consciousness. It was then Naruto remembered what happened on the bridge and got extremely angry. "Sasuke that bastard, He swapped places with me. When I see him again I'm gonna kick his ass."
Sakura nodded. "And I'm gonna do the same to Kakashi when I see him." The two looked around and saw everything and realized they are not in Nami no Kuni anymore. Naruto then asks Sakura, "Sakura-chan, where exactly are we?"
Sakura shrugs her shoulders and says, "Beats me Naruto-kun."
"You are in the Sacred Geass Temple in what remains of Uzu no Kuni." a voice came down from the hall revealing the same nun from before. "Or what it used to be called Britannia." The Nun took off her coif and veil revealing her long lime green hair that reached down the middle of her back. "Hello you two My name is C.C. and I was wondering is your last name Uzumaki young man?"
Naruto blinked. "Yeah I'm Naruto Uzumaki and this is my close friend Sakura Haruno. Ms. C.C. why do you ask?"
C.C. replied, "Because you are the emperor of this utopia, Naruto. Long before the Elemental countries. There was the Holy Britannian Empire which had 99 emperors. They believed that the staring devoured the weak until your ancestor and 99th emperor, Lelouch Vi Britannia assumed the throne and changed britannian policies for the better. Unfortunately his final plan took him away from us. But not before he gave his lover, Kallen one last gift to him, a child. That child's descendants later became the Uzumaki Clan which formed Uzu no Kuni where Britannia once stood. The geass temple was made to honor Lelouch for all he has done and I became the head nun as well as guardian of both Uzu and Britannian secrets."
As Sakura heard the story, the more she got confused and asked C.C. a question. "Uh I have a question. It sounds like you want Naruto to revive the Holy Britannian Empire but how? Uzu was destroyed like Britannia was. So how can he revive a dead country when it took his ancestors years to do?"
C.C. smiled and answered, "follow me and I'll show you." She escorted them to the basement and showed the two a door. Inside was an underground passage that reveals an underground city. C.C. then smiles at the two and says, "While the royal bloodline did perish aside from Naruto, the other uzumaki clan members survived by going citywide underground shelter. We have a legend that a Blond Uzumaki will revive Britannia from Uzu's ashes. We have restoration seals ready to restore the cities, but we need you as our ruler Naruto."
Sakura looks at Naruto worryingly and says, "Naruto, I'll be at your side no matter what choice you make. But it's up to you."
Naruto looks at the people and makes his decision. "I accept on the condition you make Sakura my empress."
When she heard that, her face turned as red as a tomato but regained her composure before kissing Naruto. "You knew my feelings for Sasuke weren't real, didn't you?"
Naruto replied, "I wouldn't have chased you for so long if I didn't."
C.C. smiled at the two before calling out to the people of former Uzu. "Members of the Uzumaki Clan, we have found our Emperor. Prepare for the rebirth of Britannia with 1st Emperor Naruto Uzu Britannia and 1st Empress Sakura Uzu Britannia." The people cheered as they began to activate the seal arrays. "Come your majesties, we must prepare for your royal wedding and coronation." C.C. then starts escorting them to the self repairing castle above ground.
