They could have many adventures. For example, they might be sent on a top - secret mission to infiltrate an enemy stronghold. Naruto's ability to make friends and his never - give - up attitude could help them gain allies within the enemy ranks, while Sasuke's sharp skills and strategic mind would be crucial for planning their every move.
Well, they could be involved in a mission to protect a very important person. With Naruto's super strength and Sasuke's Sharingan, they would be a formidable duo. Maybe they'd face some internal ANBU politics too. Naruto would probably be the one trying to keep the peace among the members, while Sasuke would be more focused on the mission's success.
One possible adventure is that they are dispatched to investigate a strange and powerful chakra source. Along the way, they'd encounter various foes and obstacles. Naruto might try to reason with some of the enemies first, using his talk - no - jutsu. Sasuke, on the other hand, would be ready to fight at a moment's notice. Their different personalities and skills would make their time in ANBU full of interesting and challenging situations.
Perhaps they embark on an adventure to investigate a series of strange disappearances in a nearby forest. Yugao's Anbu experience would be useful in tracking the culprits, while Naruto's ability to think outside the box could lead them to discover the real cause behind the disappearances, which could be some kind of dark jutsu being experimented with by an evil organization. As they dig deeper, they get into more and more dangerous situations but manage to get out of them through their teamwork.
They could go on an adventure to find a rare and powerful jutsu. Naruto would be eager to learn it, Sasuke would see it as a way to increase his power, and Shikamaru would be dragged along reluctantly at first. But during the search, they discover that the jutsu has a dark side that they must decide whether to use or destroy.
Their relationship could become more competitive. Since ANBU is a place for elite ninjas, they might constantly strive to outdo each other in missions.
They could have all kinds of adventures. Maybe they would be sorted into different houses at Hogwarts. Naruto might end up in Gryffindor with his courage. Sasuke could be in Slytherin due to his ambition. And Gaara, perhaps Hufflepuff for his loyalty in his own way. They could team up to fight against dark wizards who are threatening Hogwarts, using their ninja skills combined with magic.
Maybe they embark on an adventure to help a small, oppressed village. They use their combined skills to overthrow the tyrant ruling the village and then stay for a while to help rebuild it. During this time, they learn about different ways of life and make new friends. This adventure would strengthen their bond and also their reputations as great shinobi.
In ANBU fanfictions about Naruto and Iruka, their relationship often takes on new and exciting dimensions. Naruto, with his usual exuberance and determination, might be guided in the more secretive and dangerous ANBU world by Iruka. Iruka, being a caring figure in Naruto's life, could be a source of stability for Naruto as he faces the harsher aspects of ANBU missions.
One possible scenario in such a fanfiction could be Naruto as Hokage having to deal with political situations in the village while Sasuke, as an Anbu, is sent on dangerous covert missions. Naruto might rely on Sasuke's intelligence and combat skills from his Anbu work to protect the village from external threats. They could also have some internal conflicts due to their different roles and the secrecy associated with Sasuke's Anbu work.
Well, perhaps Naruto and Sasuke are forced to join Orochimaru. Maybe Orochimaru has some kind of leverage over Konoha that makes them comply. In this fanfiction, they could start to learn unique jutsus from Orochimaru but also have to constantly resist his more evil intentions. They might also meet some interesting characters within Orochimaru's lair.
They might encounter a group of bandits. Sasuke would use his Sharingan to quickly assess the situation and his combat skills to fight them off. Sakura would be right beside him, using her medical ninjutsu to heal any minor wounds they get during the fight.
Naruto could potentially find some ancient ninja artifacts on the deserted island. These artifacts could hold great power or knowledge. He would then have to figure out how to use or protect them. There could also be some sort of mystery on the island, like a hidden cave with strange markings. Naruto, being the curious and adventurous type, would surely try to solve the mystery. This could lead to him learning new jutsu or uncovering secrets about the ninja world's past.