They could go on a mission together to retrieve a lost ninja art scroll. Since they are the same age, they might have a competitive yet friendly relationship during the mission, constantly trying to outdo each other in combat skills but also having each other's backs.
They could explore an ancient and mysterious ninja ruin together. Naruto, with his curiosity, and Anko, with her knowledge of the ninja world's secrets, would make a great team. They would face various traps and puzzles within the ruin, and their combined efforts would be crucial in uncovering the secrets hidden there.
Perhaps they would participate in the Chunin Exams at the same time. Naruto's determination and Anko's more experienced and sly nature could lead to some interesting interactions during the exams. They might team up against a particularly tough opponent from another village, using Naruto's raw power and Anko's strategic thinking.
They could go on a mission to find a lost pet in the village. Since they are the same age, they would have similar levels of energy and curiosity. Naruto's determination and Hana's skills with animals might combine well to track down the pet and return it to its owner.
Well, they might embark on a journey to find a rare herb that has the power to heal any injury. Shizune's medical knowledge would be crucial in identifying the herb, and Naruto's strength and determination would keep them safe from any threats along the way. They could also get into all sorts of scrapes with other ninja clans who also want the herb for their own purposes.
They could go on adventures to discover ancient ninja secrets. Since they are the same age, they might team up to explore hidden places that are said to hold great power or knowledge. Maybe they would search for lost jutsu together and face various challenges along the way.
Naruto and Minato could have adventures in the spirit world together if they were the same age in fanfiction. They could face powerful spirits and learn spiritual ninja techniques. Their combined courage and determination would help them overcome the challenges there. They might also meet the previous Hokages in the spirit world and get some unique training or advice, which would be very beneficial for their growth as ninjas.
They could have training adventures together. Since they are the same age, they might compete in various ninja skills, like who can master a new jutsu faster. Maybe they'd go on missions side by side, facing challenges and relying on each other's unique abilities.
They might go on a mission to find a rare herb in a dangerous forest. Naruto's determination and Anko's knowledge of the area could lead them to the herb and also encounter some interesting creatures along the way.
He could have adventures in the Forest of Death. Anko has experience there, and she could take Naruto on more dangerous and secretive missions within that area. Naruto would learn how to better handle the perils of that forest.
Well, they could embark on a journey to find other tailed beasts and try to form a new kind of bond among them. This would be an adventure full of challenges as some of the tailed beasts might be hostile at first. Naruto and Kyuubi, as brothers, would use their combined strength and Naruto's persuasion skills to make peace with them. Along the way, they would also learn more about each other's capabilities and grow closer as brothers.
They could go on an adventure to find a powerful treasure that combines the power of the One Piece and some kind of ninja - related artifact. Maybe they'd have to fight against a new enemy that is a combination of pirates and rogue ninjas. They might travel to new islands where Naruto's ninjutsu would be useful for exploring hidden caves, and Luffy's stretching ability would help them reach high places or cross large gaps.
They could have some really cool adventures. For example, they could team up to take on a powerful villain that is causing chaos in both their worlds. Naruto's ninja skills combined with Batman's detective skills and gadgets would make for an unbeatable team. They might also go on a journey to find a way to send Naruto back to his own world if that was the case, encountering all sorts of strange creatures and obstacles along the way.