One idea could be that the baby has a unique power that combines Ichigo's Hollow powers and Rukia's Shinigami abilities. It could be a struggle for them to protect the baby from those who might want to use its power for evil.
Another idea is that the baby has a prophetic ability. It can see the future and warns Ichigo and Rukia about upcoming threats. However, they are not always sure whether to believe the baby's visions, which creates some tension in the story.
Another plot could be that there's a powerful enemy who tries to use Rukia and Ichigo's feelings against them. They have to fight not only the external threat but also their own growing desires for each other, which leads to some tense and steamy moments in the fanfiction.
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.
One idea could be that Ichigo and Rukia find themselves in an alternate universe where their roles are reversed. Rukia could be the one with the Shinigami powers from the start in Karakura Town, and Ichigo is a normal human who gradually discovers his own latent spiritual abilities to help her. Another could be that they are sent on a special mission together to a realm neither has been to before, like a dimension full of lost souls. There, they have to rely on each other more than ever to find their way back and complete their task.
One plot idea could be that Hollow Ichigo and Rukia are forced to team up against a new, powerful enemy that threatens both the Soul Society and the world of the Hollows. They start off distrusting each other but gradually learn to work together and understand each other's motives better.
One idea could be that Arrancar Ichigo has to protect Rukia from a new, powerful enemy in Hueco Mundo. Since he has Arrancar powers, he has a different fighting style and perspective, which could lead to some really intense battle scenes and a deeper understanding between them.
The new addition to their family could also make them more open about their feelings for each other. They might realize how much they truly care for one another while watching their baby grow. This could lead to more affectionate moments between them and a more solid romantic relationship.
Well, it could be about their baby having some sort of special power. Maybe the baby inherits both rukia's shinigami powers and ichigo's hybrid powers. It could grow up in a world where it has to learn to control these powers while also facing the challenges of being the child of two very important and powerful beings.
There are fanfictions where Ichigo and Rukia are in a modern-day high school setting. They still have their powers but have to keep it a secret. This type of fanfiction often focuses on their relationship development in a more normal, day - to - day environment, with some comical moments when they almost expose their powers by accident.
One interesting Ichigo and Rukia fanfiction could be about their adventures in a modern-day world where they have to hide their Soul Reaper powers. They might go to school together and face normal teenage problems while also dealing with Hollows that pop up in the city.
One idea could be that Ichigo, Rukia, and Orihime discover a strange lemon - shaped spiritual artifact. They have to figure out its powers and how it relates to the Soul Society. Maybe it has the power to enhance their spiritual abilities, but also comes with a strange side - effect that changes their relationships in unexpected ways.