Perhaps there is a human scientist who discovers a way to cross into the Bleach universe and brings along an army of technologically advanced humans. They might try to impose their own order on the world of Bleach, which would cause a great deal of conflict with the existing spiritual beings. This could lead to alliances being formed between different factions in the Soul Society and Hueco Mundo to fight against the human invaders.
One idea could be that the humans find a way to access the Soul Society without permission, leading to chaos as they start to explore and misunderstand the different realms. Maybe they accidentally release some dangerous Hollows in the process.
A cool plot for a 'bleach sleepover' fanfic could involve the characters from different factions in 'bleach' coming together for a sleepover. For example, the Shinigami and the Arrancar. At first, there's tension, but as the night progresses, they start to understand each other better. They could play games like truth or dare, which leads to some really interesting character revelations and unexpected alliances forming. This could also set the stage for future interactions in the 'bleach' universe outside of the sleepover.
Perhaps a 'bleach school fanfic' could focus on the relationships between students. For example, two characters who are normally rivals have to team up for a project. They slowly learn to understand and respect each other's abilities. Or it could be about a group of students trying to solve a mystery that is plaguing the school, like strange disappearances that seem to be related to some dark spiritual force.
One idea could be a dragon from a hidden realm in the Bleach universe emerging and forging an alliance with Ichigo. The dragon could have unique powers that help Ichigo in his battles against the Hollows. For example, it might be able to breathe a special type of reiatsu - infused fire that can purify Hollows more effectively than a normal Soul Reaper's sword.
A possible plot for a 'bleach swinging pendulum fanfic' could be centered around the idea of moral pendulum swings. Characters who were once considered 'good' in the Bleach world start to question their actions and motives. For example, Soul Reapers who have always been about maintaining order might find themselves in situations where their traditional methods seem cruel or unjust. This could lead to internal conflicts within the Soul Society. On the other hand, some Hollows might experience a change towards redemption. The story could explore how these moral shifts affect the relationships between different factions and the overall dynamic of the Bleach universe.
One idea could be that a powerful Soul Reaper takes on a young and inexperienced one as a sort of apprentice in a master - slave relationship. The master could teach the slave about different zanpakuto techniques and the ways of the Soul Society. For example, they could go on missions together where the master protects the slave at first but gradually lets the slave take on more challenges.
One idea could be to explore an alternate timeline where Ichigo never became a Soul Reaper. Maybe he lives a normal life, but strange spiritual events still occur around him, drawing him into the world of the Hollows and Soul Reapers in a different way. Another idea is to focus on a side character, like Uryu, and tell a story from his perspective during a major arc that we didn't see much of in the original series. For example, his experiences during the Arrancar arc when he was off on his own missions.
A new human character could be introduced, like a military leader who is leading the invasion. He could have his own motives for wanting to take over the Soul Society, such as a thirst for power or a belief that humans should control all realms.
One idea could be a dragon who is injured and is found by a human. The human nurses the dragon back to health and they form an unbreakable bond. Then they go on adventures together, facing various challenges in a magical world.
One idea could be a human being accidentally transported to the Beastars world and having to navigate the complex social hierarchy between different species. For example, they might initially be feared by some animals due to being a human, but then gradually earn the trust of certain characters through acts of kindness. Another plot could involve a human who has unique knowledge from their own world, like advanced medical techniques, and uses it to help the animals in Beastars. Or perhaps a human gets involved in the school drama at Cherryton Academy, befriending some of the main characters like Legoshi and Haru and getting caught up in their relationships and rivalries.
One interesting plot idea could be Karin discovers she has a new spiritual power that Toshiro helps her control. They go on a journey together to figure out the origin of this power, facing various Hollows along the way. This would bring them closer as they rely on each other's skills.