Perhaps Ichigo is hurt in a fight against a rogue Shinigami. This Shinigami has a special ability that can nullify Ichigo's Bankai temporarily. Without his Bankai, Ichigo is at a disadvantage and gets seriously injured. Rukia could then try to hold off the enemy while Ichigo recovers some of his strength.
In a fanfiction, Ichigo might be hurt during a mission in the World of the Living. He encounters a group of powerful Quincy who have a new weapon that can harm his soul directly. The Quincy target him because they see him as a threat to their new order. His family and friends in the World of the Living would then have to protect him while he heals.
One possible fanfiction could be that Ichigo gets hurt while facing a new and extremely powerful Hollow. He might be caught off - guard during the battle, the Hollow's unique attack managing to pierce through his defenses and wound him severely. His friends then have to step in to protect him while he tries to regain his strength.
One plot idea could be that Ichigo and Halibel are forced to team up against a new, powerful enemy that threatens both their worlds. They start off distrusting each other but gradually learn to respect and rely on one another's strengths.
A plot could involve Ichigo being trapped in the Hollow world and having to find a way back. Along the way, he meets other Hollows with different personalities and motives, some of whom he befriends while others are enemies. He discovers secrets about the origin of Hollows and how it relates to his own powers.
Maybe in the fanfiction, there's a threat that only Ichigo and Unohana can face together. They have to combine their different fighting styles, with Ichigo's brute strength and Unohana's precise and deadly techniques, to overcome the enemy. For example, they might encounter a powerful Hollow that has the ability to nullify most spiritual attacks, so they need to rely on their physical combat skills and teamwork.
One plot idea could be that Ichigo and Eragon meet in a dimension that is a cross - between their two worlds. They have to team up to fight a common enemy that is threatening both of their universes. Their different powers, Ichigo's Soul Reaper abilities and Eragon's dragon - riding and magic, would make for an interesting combination in battles.
One interesting plot idea could be a story where Shirosaki and Ichigo are forced to team up against a new, powerful enemy that neither can defeat alone. This would require them to put aside their differences and learn to work together, leading to some tense and interesting character interactions.
Another plot could be that an ancient evil force targets Femichigo because she represents a new and unknown power in the Bleach universe. Ichigo vows to protect her at all costs. Along the way, they discover secrets about their connection that were hidden by the Soul Society, and they have to fight against not only the external threat but also the political intrigue within the Soul Society.
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 great aspect of Bleach Ichigo and Rukia fanfiction is the exploration of their relationship beyond the original story. Writers often delve into their deep bond, showing how they support each other in different situations. It could be in the face of new threats in Soul Society or just in their daily lives. Fanfiction gives a chance to expand on their characters and how they interact, which is really interesting for fans of the series.
Another idea for the fanfiction could be a time - travel plot. What if Ichigo somehow travels back in time and meets a younger Rangiku? He could influence her growth and development, and in turn, she could have an impact on his view of the past. This would create a complex web of cause and effect, and it would be interesting to see how their actions in the past would shape the future of the Bleach world they know.