One possibility is that the reverse summoning is part of a secret jutsu gone wrong. Gojira's arrival might disrupt the balance of chakra in the Naruto world. The plot could involve Naruto seeking out ancient scrolls or wise sages to understand how to deal with this unexpected situation. He might also have to team up with his friends, like Sasuke, to control Gojira's power and prevent it from destroying everything.
Sakura would probably be terrified at first. She might initially think it's a new kind of giant summon gone wrong. But then she would gather her courage and try to help Naruto deal with the situation, maybe using her medical skills to heal any injured people in the chaos. Kakashi, on the other hand, would be very calm and start observing Gojira's behavior to figure out a strategy.
One plot idea for a snake summon Naruto fanfic is that there is a prophecy about a chosen one who can fully control the snake summons. A young girl from a far - off land believes she is this chosen one. She travels to the Hidden Leaf Village to find Naruto, thinking he can help her fulfill her destiny. Together, they unlock the true potential of snake summons and use it to save the ninja world from a dark force that is slowly consuming all the chakra in the land.
A possible plot could be that the rat summons are in danger. Some dark force in the ninja world is hunting them down for their unique chakra or some other special ability they possess. Naruto has to protect his rat summons and in the process, he uncovers a conspiracy that is much larger than he expected, involving multiple villages.
The plot could be that Naruto accidentally summons the leopard instead of his normal toads during a battle. The leopard is initially hostile but Naruto manages to convince it to help him. They then form an unexpected bond and the leopard becomes Naruto's secret weapon.
One possible plot could be that Naruto discovers an ancient scroll that reveals the secrets of the monkey summon. He then embarks on a quest to find the monkey summon. Along the way, he has to face various challenges and enemies. Once he finally summons the monkey, it could be a powerful ally that helps him in battles against stronger foes like the Akatsuki members.
Well, one possible plot could be that Naruto, in his focus on other things like becoming Hokage and protecting the village, completely overlooks a powerful god - like summon. Maybe this summon has unique abilities that could have been a great asset to him. For example, it could have the power to control the elements in a way no other summon can. As a result of being neglected, the summon might grow resentful and start causing problems in the ninja world. This could then lead to Naruto having to face the consequences of his neglect and find a way to make amends with the summon.
The plot could be that the snake summon discovers a hidden lemon grove in the ninja world. This grove has some kind of special chakra - infused lemons. Naruto and the snake have to protect these lemons from an evil ninja clan who wants to use their power for bad. It could lead to an epic battle where the snake uses its unique abilities along with the lemons' power.
One idea could be a pony being summoned in the Naruto world and having to adapt to the ninja way. For example, it might use its unique pony abilities like magic or flight in combat, which would surprise the Naruto characters.
The crow summon in Naruto fanfic often adds an element of mystery. Crows are associated with intelligence and stealth in many cultures, and in Naruto's world, they can be a great addition to a character's abilities. A fanfic might explore a character who has a special bond with the crows they summon, and through this bond, they gain unique powers or insights.
The ability to summon foxes might make Naruto more of a target. Villains would be interested in his new power. This could lead to more dangerous and complex storylines as Naruto has to not only protect himself but also the foxes he summons. It could also lead to new alliances as other characters see the potential of the foxes in the fight against common enemies.