A possible plot idea is that the main character discovers a new type of physical henge that no one has ever seen before. This new henge could give them unique abilities, like the ability to blend in with the environment in a way that normal henges can't. They could then use this to their advantage in battles or to spy on the enemy. Also, a plot could revolve around a henge competition where ninjas show off their best and most creative henges, and the main character has to come up with something really special to win.
One idea could be a character using the physical henge in creative ways during a mission. For example, they could henge into a large beast to intimidate the enemy, but then quickly change to a small insect to slip through a tight security area. Another plot idea could be a character accidentally getting stuck in a wrong henge form and having to figure out how to reverse it while in the middle of a dangerous situation. Maybe they henge into an enemy ninja by mistake and have to act like them to avoid being discovered.
Perhaps a fanfic where Naruto's Solid Henge goes wrong and he accidentally creates a bunch of strange and uncontrollable objects. This could lead to a comical adventure as he tries to fix his mistakes with the help of his friends like Sasuke and Sakura.
One idea could be that Naruto uses the Dragon Henge to infiltrate a secret organization that has a dragon as its symbol. He could gather intelligence while in the form of a dragon.
One idea could be the main character, who is a henge master, getting involved in a mission where they have to use their henge skills to infiltrate an enemy stronghold. They could transform into various characters to gather intelligence.
One idea could be that Naruto uses his transformation jutsu (henge) to transform into Latias. He could then use Latias' abilities like flying and psychic powers to his advantage in a battle. Maybe he's in a new, strange land where Pokémon exist and has to blend in by using the henge.
One idea could be Naruto using the Solid Henge to create complex and long - lasting structures for strategic purposes in a battle. For example, he could make a huge fortress that the enemy has to break through, adding an interesting twist to the fight.
One idea could be a character using the permanent henge to blend into an enemy village and discover their secrets. For example, Naruto could use it to look like a random civilian in the Sand Village and find out about their new defense strategies.
One idea could be that Naruto uses his henge to transform into Inari to teach the real Inari a lesson about self - confidence. He could go through a day in Inari's life, facing the same challenges Inari does, but handling them in a more positive way, inspiring the real Inari to change.
One idea could be Naruto using his henge to transform into the Kyuubi in a different way than expected. For example, instead of just looking like the Kyuubi, he could also gain some of its powers in a limited form while in the henge. This could lead to him surprising his enemies and allies alike.
In a Naruto physical henge fanfic, the concept of physical henge can be a great way for character development. Imagine a character who is afraid of heights. They could use the physical henge to transform into a bird and face their fear. Through this experience, they could gain courage and self - confidence. Another way is that a character could henge into an older version of themselves to see how they might develop in the future. This can give them insights into their goals and what they need to do to achieve them. Moreover, characters can use henges to understand different cultures or species within the Naruto world, which broadens their perspective and helps in their development.
One idea could be Naruto using the Henge no Jutsu in creative ways during a mission. For example, he could transform into a famous ninja from the past to deceive the enemy. Another idea is that Naruto accidentally henges into a different form that has unexpected powers.