The fact that they are both jinchuriki could be a challenge. They have a great power within them that many might fear or try to control. Enemies could target them because of their status, which could endanger not only them but also their relationship. They would have to constantly be on guard and this could cause stress in their relationship.
One challenge could be their different villages. Naruto is from Konoha and Yugito is from Kumo. Their villages might have political tensions or different agendas that could put a strain on their relationship. For example, if there is a conflict between the two villages, they might be forced to choose between their love and their loyalty to their respective villages.
Another challenge could be cultural differences. Konoha and Kumo have different cultures, traditions, and ways of life. These differences could lead to misunderstandings between Naruto and Yugito. For instance, their views on family, relationships, or even how to handle power could be very different, and they would need to work hard to overcome these differences to make their relationship work.
Financial problems could be an issue. If they are just starting out in the modern world, finding good jobs might be tough. Naruto, with his impulsive nature, might make some bad financial decisions at first. And Yugito, who is used to a different kind of economy in the Naruto world, would have to adjust to things like paying rent, bills, etc. Also, they might face discrimination from people who sense that they are different, even if they don't know about their ninja powers.
One challenge could be adapting to the team's dynamics. Team 8 has its own way of operating, and Naruto is used to his own style with his friends. For instance, they might be more methodical in their planning, while Naruto is more of a 'jump - in - and - figure - it - out' type. So, he'd have to learn to follow their lead sometimes.
He might face challenges like finding the right place to plant the tree. Konoha has a lot of regulations about what can be planted where. Also, he needs to make sure the tree gets enough water and sunlight. If it's a magical tree, he may not know exactly what it needs to grow well.
One challenge could be controlling the power of the Juubi. It's an incredibly powerful and chaotic force. Naruto would have to struggle to keep it in check so that it doesn't overwhelm him and cause him to lose control. If he loses control, he could end up harming his friends and allies instead of protecting them.
One challenge could be dealing with competitors. If his company is in a competitive field like ninja training, there might be other established companies or individuals who see him as a threat and try to undermine his business.
One challenge could be the cultural shock. Naruto is used to the ways of the ninja villages, and New York has a very different culture. Another challenge might be the language barrier. He would need to communicate with people in New York, and English might not be his strong suit. Also, the different fighting styles in New York compared to his ninja skills could pose a problem.
One challenge could be that the enemy is too powerful for Naruto to defeat on his own. He might have to quickly level up his skills or find allies to help him. For instance, he might need to convince some of the more reluctant ninja in the village to join him in the fight.
One challenge Naruto might face is dealing with the physical changes in the Kyuubi. Since it's a unique situation, he may not know how to properly support the Kyuubi during the pregnancy. Another challenge could be facing the judgment of the villagers. They may be afraid or not understand what's going on and turn against Naruto.
Kawaki might resist Naruto's teachings at first. Since he has his own way of doing things, adapting to Naruto's values and training methods could be difficult. Also, the village might not fully accept Kawaki right away, and Naruto would have to fight for Kawaki to be accepted, which is a big challenge.
Naruto would face the challenge of resources. Orochimaru had his own ways of obtaining resources, some of which were unethical. Naruto would need to find legitimate ways to sustain Oto, whether it's through trade, alliances, or new forms of income generation. He also has to deal with potential threats from other ninja villages. They might see Naruto's leadership of Oto as a threat or an unknown variable and could take preemptive actions against Oto.