In a fanfic, their relationship could develop through shared hardships. For example, they could be trapped in a dangerous situation like a cursed forest. As they struggle to survive, they learn more about each other's fears and hopes. This deepens their connection and they start to rely on each other more, gradually evolving into a closer relationship.
One interesting plot idea could be that Naruto and SumoMomo Momomo team up for a special mission in a new, unexplored land. They face various challenges together, like strange new jutsus from the local ninjas and difficult terrains. This would allow for their characters to develop a unique bond as they rely on each other's skills.
Well, it's hard to say for sure. The concept of 'porn-like' is quite subjective. Some might consider certain novels with excessive sexual descriptions as such, but it depends on individual perspectives and cultural standards.
In many places, 18+ porn comics are considered illegal. This is because they can have a negative impact on society and violate moral and legal standards.
The main distinction of porn with a story genre from regular porn is the presence of a coherent narrative. Regular porn often jumps straight to the sexual action, while the story genre tries to add some kind of story framework around it. But in the end, both are adult-oriented and feature explicit sexual content.