Perhaps in this fanfiction, Cana's pregnancy is a result of a magical accident. Naruto, being the determined and loving person he is, tries to learn about Cana's world of magic to better support her during the pregnancy. They could also face a villain who wants to use the unborn child for some dark purpose, leading to a big battle where Naruto and Cana fight together to protect their future family.
One possible plot could be that Naruto and Cana are from different worlds that somehow collide. They meet and fall in love. When Cana discovers she is pregnant, they face challenges from their respective communities. Naruto's ninja world might be against the union due to Cana being from a different realm, and Cana's side might have issues with Naruto's ninja lifestyle.
In the 'natsu gets cana pregnant fanfiction', perhaps it starts with a magical accident. Natsu and Cana might be exposed to some strange magic that causes an unforeseen bond between them. As a result, Cana discovers she is pregnant. Then, they would have to face the reactions of their friends and the challenges that come with this new situation in their lives.
One idea could be that they discover their pregnancy during an important mission. This would add a layer of complexity as they have to balance their new situation with their duties. They might have to face the reactions of their friends in the guild, some being overjoyed and others worried. Another plot could involve them preparing for the baby's arrival, like Natsu trying to build a nursery with his unique brand of enthusiasm but making comical mistakes along the way.
One possible plot could be that it's an alternate universe where Naruto and Tenten end up together in a situation that leads to pregnancy. Maybe they were on a mission together and some strange magic or jutsu affected them, causing Tenten to become pregnant. They then have to deal with the reactions of their friends and the challenges of impending parenthood.
The plot could be that Naruto and Mei are in a secret relationship. When Mei gets pregnant, they try to keep it a secret at first. However, as the pregnancy progresses, it becomes harder to hide. Mei starts to show signs of a special chakra within her womb, which makes some villains target her. Naruto has to fight off these villains while also dealing with his own insecurities about becoming a father. They finally decide to reveal their relationship and Mei's pregnancy to their closest friends and allies, who then rally around them to protect them and the unborn child.
One possible plot could be that Naruto and Shion's relationship develops gradually. Shion discovers she's pregnant and they face challenges together. For example, they might have to deal with the reactions of their friends and the village. Naruto would be protective, using his skills to keep Shion and the unborn child safe from any threats.
One possible plot could be that they accidentally get caught in a jutsu that causes Konan to become pregnant. Naruto, being the responsible person he is, decides to support her fully. They might face challenges from their respective villages as their relationship was unexpected. Konan may have to deal with the physical and emotional changes during pregnancy while Naruto tries to protect her from any harm.
Perhaps in this fanfiction, an evil force has a plan that involves Azula getting pregnant with Naruto's child. The two initially don't get along but as the pregnancy progresses, they start to understand each other better. Naruto teaches Azula about his ninja values like friendship and hard work, while Azula shows Naruto some of the strategic skills from her world. And they work together to protect their unborn child from the evil force.
A plot could involve the challenges they face during the pregnancy. Maybe there are threats from old enemies who see the baby as a potential target. Naruto and Temari then have to take extra precautions to protect themselves and the unborn child. They could also go on a journey to find a special kind of medical ninja who can ensure a safe pregnancy for Temari, especially if there are some complications due to her being a ninja. Along the way, they might discover new things about each other and grow even closer as a couple.
One plot idea could be that they face challenges together during the pregnancy. For example, they might have to deal with threats from enemies who see their unborn child as a potential threat or a valuable asset. Naruto's experience and skills, along with Yugito's, would be put to the test as they protect their family.
One possible plot twist could be that there is some sort of magic or jutsu involved that endangers the pregnancy. For example, a dark magic user might target Mirajane because of her unique powers and the fact that she is pregnant, seeing the unborn child as a potential threat in the future. Another twist could be that Naruto discovers a new form of chakra that can only be accessed through the combined efforts of him and Mirajane during her pregnancy, which then becomes crucial for saving their world from a great evil.