Another option is to have Hinata and Numbuh Three as the main characters. Hinata's shyness and her growth in Naruto could be paralleled with Numbuh Three's own journey of self - discovery in the KND. They could support each other and show different aspects of courage in the face of challenges.
Numbuh One is a popular choice. As the leader, he has a lot of responsibilities and his leadership skills can be explored further. For instance, you could write about his decision - making process during a difficult mission.
One idea could be a crossover where the Naruto characters visit the world of the Kids Next Door. Maybe Naruto and his friends join the KND in one of their missions against the adults. Another idea is to have the KND use some of the ninja techniques from Naruto, like Naruto teaching them how to do the shadow clone jutsu.
Boruto, of course, is an obvious choice as he is Naruto's son. He already has a lot of development in the official series, but in a fanfic, you could explore his growth in different directions, like if he had to take on a much greater responsibility at a younger age.
The main characters are the members of the Kids Next Door. There's Numbuh One, who is the leader. Numbuh Two, who is good with gadgets, Numbuh Three, a girl with her own charm, Numbuh Four, the tough one, Numbuh Five, the smart and sassy one, etc.
Maybe a young woman who lives in a house and the male ghost next door. The woman could be curious about the strange happenings in the neighboring house which are caused by the ghost, and that could be the start of their relationship.
The street kids themselves would be main characters. They could be a diverse group with different personalities and backstories. There might also be Naruto's friends like Sakura and Kakashi who could play important roles. Sakura could help with the kids' medical needs, and Kakashi could offer his wisdom in training the kids.
A great plot might involve the kids forming a secret club in high school that's like a successor to their Kids Next Door operations. They face challenges from a rival high - school group who also have their own 'undercover' activities. The story could focus on the battles between the two groups, both academically and in their secret missions. For example, competing for control over the school's abandoned attic which they both want for their own purposes.
The main characters would be the widowed cougar, who is likely a confident, independent woman in her 40s or 50s. And the neighbor, who could be a younger man, maybe in his 20s or 30s, who is either single or just out of a relationship.
I'm not entirely sure specifically about Count Spankulot in the 'Codebame' related 'Kids Next Door' fanfic. It might be a very niche or even a made - up scenario within the fan - created content. Maybe it involves Count Spankulot having some sort of unique role or adventure within the world of the Kids Next Door as reimagined in that fanfic.
The clash of different universes. For example, if it's a 'kids next door' crossover with 'Teen Titans', the different powers and personalities make it exciting. Robin's leadership in the Teen Titans against the more chaotic but organized KND is a great dynamic.