One interesting plot could be that the villains from both universes team up. The Akatsuki from Naruto and the Dark Kingdom from Sailor Moon might join forces to collect powerful artifacts. Naruto and the Sailor Scouts would then have to put aside their differences in fighting styles and powers to defeat this new, combined threat. They could learn from each other's combat techniques. For example, Naruto might teach the Scouts about his shadow clone jutsu, while Sailor Moon could show Naruto how to use the power of love and friendship in a more direct way to boost his power in battles.
One interesting plot could be that the Sailor Guardians are on a mission to a world similar to Naruto's. There, they meet Naruto and his friends. Naruto is initially confused by their strange powers but quickly realizes they can help fight a common enemy. Maybe an evil force from the Sailor Moon universe has teamed up with Orochimaru. The Sailor Guardians' magic combined with Naruto's ninja skills could make for some epic battle scenes.
One possible plot could be that Naruto and his friends are transported to the Sailor Moon universe. Naruto's chakra could be seen as a similar power to the Sailor Scouts' magic. They could team up to fight a common enemy, like an evil force that is draining both the chakra and the magic energy in both universes. Naruto's determination and the Sailor Scouts' love and justice - driven powers could combine in unique ways to defeat the foe.
Maybe the NCIS team stumbles upon a strange artifact that has the power to open portals to different dimensions. Unknowingly, they activate it and end up in the world of Sailor Moon. There, they meet Sailor Moon and her friends who are in the middle of a battle against the forces of evil. The NCIS agents, with their knowledge of forensics and combat skills, offer their help. In return, the Sailor Scouts teach them about the magic and powers in their world. Together, they form an unlikely alliance to defeat the common enemy.
A plot might involve Sailor Moon herself getting lost in the Underworld. As she tries to find her way back, she discovers that there are some similarities between the magic in the Underworld and her own powers. She could meet a character in the Underworld who has a connection to her past or her future. Together, they start to uncover a mystery that links the two worlds and has the potential to either save or destroy both.
One possible plot could be that the Sailor Scouts are facing a new and extremely powerful enemy that they can't defeat on their own. Goku and his friends from Dragonball Z sense the danger across the dimensions and come to help. The Scouts are initially shocked by the Saiyans' power levels but then start to learn from them about ki control. Together, they combine their powers, like the Sailor Scouts using their magic with the Z - fighters' ki blasts to take on the foe.
Perhaps a malfunction in the Steel Angel's programming sends them to the Sailor Moon world. The Sailor Scouts mistake them for new enemies at first. However, as they learn more about the Steel Angels' origin and mission, they decide to work together. They could face a threat that requires both the Sailor Scouts' celestial powers and the Steel Angels' combat skills. For example, an ancient evil that can only be defeated by a combination of magic and advanced technology.
Well, perhaps there's a villain who has the ability to steal the essence of both the armors of the Ronin Warriors and the transformation items of the Sailor Scouts. The two groups have to team up. The Ronin Warriors could teach the Sailor Scouts some combat skills, while the Sailor Scouts could show the Ronin Warriors how to use magic more effectively. They'd then go on a journey to recover their lost powers and defeat the villain.
One possible interesting plot could be that Naruto and Sailor Moon somehow end up in the same dimension due to a strange magical rift. Naruto, with his ninja skills, and Sailor Moon, with her magical powers, have to team up to fight a new common enemy that is causing chaos in this merged world. They start off not understanding each other's abilities but gradually learn to combine their powers for greater effect.
Well, one possible plot could be that the Sailor Scouts are transported to the Pokemon world. They might team up with some Pokemon trainers to fight against a common enemy. Maybe an evil organization is trying to use both the power of the Dark Kingdom from Sailor Moon and some powerful, dark Pokemon. The Sailor Scouts' magical powers could interact in interesting ways with the Pokemon's abilities.
Maybe there could be a villain that is causing problems in both worlds. The Sailor Scouts and Ranma could team up to fight this villain. Ranma's martial arts skills combined with the Sailor Scouts' magical powers would make for an interesting battle. They might have to learn to work together despite their very different fighting styles and personalities.