Perhaps in the fanfiction, their pregnancies could be a result of some magical or supernatural event. This could lead to a story where they have to figure out not only how to handle the pregnancies but also the implications of the strange circumstances that led to them. For example, they might have to seek help from powerful beings to ensure the health of their unborn children.
One plot idea could be that they discover their pregnancies around the same time and form an unexpected bond as they navigate the challenges together. They might support each other through the physical and emotional changes, sharing tips on dealing with morning sickness and mood swings.
Another idea is that their pregnancies could cause a stir in the community they belong to. There could be different reactions from friends, family, and foes. Some might be supportive, while others could see it as a weakness or a threat. Rukia and Karin would then have to deal with the social aspects while also preparing for motherhood.
In a fanfiction like this, the plot could revolve around Karin's pregnancy being a result of some sort of experimental jutsu gone wrong. Naruto, being the hero he is, feels responsible for her well - being. They might have to go on a journey to find a way to reverse the effects of the jutsu if it's dangerous for Karin or the unborn child. Along the way, they face various enemies and also form a deeper bond as they deal with this unexpected situation.
One idea could be exploring their family history. Maybe they discover they have a common ancestor who was a powerful ninja. This could lead to them uncovering hidden jutsu or secrets within their family lineage.
One possible plot idea could be the challenges they face within the Soul Society while being pregnant. For example, they might have to deal with the traditional expectations and rules of the Soul Reaper community. Another idea could be how their relationship changes and deepens during this time. They could grow closer as they anticipate the arrival of their child, sharing new experiences and emotions.
One idea could be that their pregnancy is a result of some kind of magical or spiritual event in the Bleach universe. Maybe an ancient spell gone wrong or right, depending on how you look at it. For example, a spell that was meant to protect Soul Society actually ends up causing Rukia to become pregnant. Another plot could involve the two of them having to hide the pregnancy at first because it goes against some Soul Reaper rules or traditions. They then have to deal with the consequences of keeping it a secret while also preparing for the arrival of the baby.
Perhaps the fanfiction could focus on how Toshiro and Karin prepare for the arrival of the baby. They could be redecorating their home, shopping for baby items, and Toshiro could be learning how to be a great father. There could also be a sub - plot where Karin is worried about how her life will change after the baby is born and Toshiro is there to comfort her.
Well, perhaps the fanfic could focus on how their relationship evolves during the pregnancy. Rukia, being a strong Soul Reaper, might initially struggle with the idea of being more vulnerable due to the pregnancy. And Ichigo could be overly protective. They could also face opposition from the Soul Society, which adds a lot of drama to the story.
One idea could be exploring how Yennefer deals with the physical and emotional changes during pregnancy while still being a powerful sorceress. Maybe she has to find a way to protect her unborn child from the many enemies she has made.
One idea could be exploring how she and her partner (like Percy) adjust to the news. They might have to deal with the reactions of their friends and family. Another could be the challenges she faces during the pregnancy, like her still wanting to be involved in heroic adventures but having to be more cautious.
One idea could be exploring how Gwen's friends and family react to the news. Some might be overjoyed while others could be worried. Another plot could involve Gwen dealing with the physical and emotional changes during pregnancy while also trying to maintain her normal life, like her hobbies or job. And a third could be about the father's role, if known, and how their relationship evolves during this time.
A plot could revolve around Kushina having premonitions about the future of her unborn child during her pregnancy. She might have dreams that she tries to interpret, and this could add an element of mystery. Also, it could be interesting to see how her pregnancy affects her ninja duties, if she has to take a break or if she finds new ways to contribute while pregnant.