His friends from the village could be his customers. They might need seals for their various missions or personal use.
Other ninja villages' representatives could be customers. They might be interested in Naruto's unique seals to gain an edge in their own village's defense or offense. Also, some of the civilian merchants in Konoha could be customers. They may use the seals for protecting their goods or for some business - related magic.
Well, considering Naruto's own experiences and the variety of seals in the Naruto universe, he could sell communication seals. These would allow ninjas to send messages over long distances. He might also sell seals that are related to elemental jutsu, perhaps ones that enhance or modify fire, water, wind, earth or lightning techniques.
There is a possibility that it was an ex - shinobi who had retired from active duty. This person had amassed a collection of seals during their career and now made a living by selling them to other ninjas like Naruto.
Perhaps Naruto was in a situation where he had made a deal. For example, he promised to pay for the seals in exchange for some information about a missing nin or a secret technique. He values knowledge and power, and if paying for the seals was part of getting closer to achieving his goals, he would do it.
His old ninja friends like Sasuke, Sakura could be regulars.
Some of the older villagers who have watched Naruto grow up would be regulars. They would come to support his business and also to reminisce about the old days. And don't forget the jonin who are always on the lookout for a good meal. They would appreciate Naruto's hard work and the unique atmosphere of his restaurant.
Ninjas, of course! They would come to relax after a long day of training or missions. Also, fans of the ninja world from within the story would be there. Maybe even some of the village leaders would stop by to show support for the local business.
His ninja friends like Sasuke, Sakura, and Kakashi would surely be regulars. Sasuke might come to buy things secretly to support Naruto's business. Sakura could be there to get supplies for her medical ninja work if it's a general store. And Kakashi would stop by for a chat and to pick up some new reading material if Naruto sold books.
The seals could also be a plot device for a darker storyline. Maybe they were placed by an unknown enemy to control Naruto or use him as a weapon. In some fanfictions, the seals start to affect Naruto's mental state, causing him to have inner struggles between his normal self and the influence of the seals.
The answer is no. Naruto as a fictional character doesn't engage in selling fanfiction. Fanfiction is a form of fan - created content that exists outside the official commercial activities of the Naruto franchise. The official Naruto products are focused on things like the original story in manga and anime form, along with related toys, clothing, and other merchandise.
Naruto would definitely be one of the main customers. He has a well - known love for candies. His friends like Sasuke and Sakura might also stop by sometimes. Then there are the younger ninja trainees who are always looking for a sweet treat after a hard day of training.