I don't know for sure since I haven't read it. But most likely, the main character would be the kage. There could also be other important ninja characters in the village, like the kage's advisors or some powerful ninja warriors who play significant roles in helping the kage fulfill their duties.
Well, it could be about the duties of a kage in a fictional ninja world. Maybe it focuses on how a kage has to protect the village, make tough decisions regarding security, and deal with internal and external threats.
The godchild would also be a main character. They might start as an innocent youth who gradually discovers the truth about their godfather's world and has to decide what to do about it.
Obviously Naruto is one of the main characters. Since it's related to the Chunin Exams, his friends like Sasuke and Sakura are likely to be important as well. And the kage who is involved in the story would also be a main character, as they play a crucial role in Naruto's journey during the exams.
The Kages themselves are often main characters. For example, Tsunade from Konoha, Gaara from Suna, and the other village leaders. They play important roles in the political and power - related discussions during the summit.
Obviously Naruto would be one of the main characters as the title implies he's the one attacking. And the Kages, like Gaara, Tsunade, and the other village leaders would also be main characters since they are at the summit that Naruto is attacking.
The Kage Fujin is likely to be one of the main characters. They are probably a powerful figure with unique abilities related to the elements or some other special power.
I'm sorry, but without having read the 'kage no jitsuryokusha web novel', I can't tell you who the main characters are. It could be a young hero on a quest, a wise mentor, or a group of friends with different skills. But this is just speculation.
In a 'naruto wave kage fanfic', Naruto is almost always a main character due to his significance in the Naruto universe. The Kage are also central as they represent the leadership of their respective villages. The Wave Village might introduce characters like Tazuna or Inari as main characters too. Tazuna was important in the original Wave arc in Naruto. His skills as a bridge - builder could play a different role in the fanfic, like being a symbol of hope for the Wave Village in a time of conflict involving the Kage. Inari, with his growth and potential, could also have a major part in the story, perhaps forming an unexpected bond with one of the Kage.
I'm not sure as there are many novels that could potentially have 'duty and honor' in their themes. However, typically, there could be a noble - hearted protagonist who is deeply committed to his or her duty and has a strong sense of honor. Maybe a knight or a police officer type of character.
I don't have the exact information on the main characters as I'm not familiar with this particular light novel. But typically, in a light novel, there are protagonists who drive the story forward, antagonists who create conflicts, and perhaps some supporting characters who add depth to the plot.