One possible plot could be that Ichigo is hit by a strange Hollow attack that not only changes his physical form to a girl but also gives him new powers. He then has to adapt to this new body while still facing the usual threats in the Bleach universe. His friends might initially be shocked but quickly accept him and help him figure out how to reverse the transformation while still using his new - girl - form - related powers to fight enemies.
In a 'bleach ichigo turns into a girl fanfiction', perhaps there is a powerful and mischievous spirit that decides to play a prank on Ichigo. Transforming him into a girl. Ichigo, now in a female body, has to attend Soul Reaper Academy again as the teachers think it's a new student. He has to prove his skills all over again, which is difficult as he has to adjust to the new body mechanics. His relationships with his friends like Rukia and Uryu also change as they try to understand this new Ichigo and help him find a way to turn back to his male self.
Well, in a 'bleach ichigo turns into a girl fanfiction', the plot might revolve around a magical artifact. Ichigo accidentally activates it during a battle. As a girl, he discovers that his reiatsu has a different feel. He has to deal with the Hollows who now underestimate him because he's a girl. Meanwhile, some of his friends start to develop different kinds of feelings towards him. But Ichigo is determined to get back to his original form and find out who set up this whole situation.
One possible plot twist could be that Ichigo, now as a girl, has to deal with different power dynamics. Maybe her reiatsu (spiritual pressure) is affected in a new way. For example, it could become more refined or have a different color, which would attract different kinds of Hollows or Soul Reapers. Another twist could be in her relationships. Her friends might initially be shocked and not know how to interact with her. Uryu, for instance, might be more hesitant to be around her at first. Also, the Soul Society's reaction could be interesting. They might be suspicious of this change and think it's some kind of new threat or a trick by the Quincy. Overall, the story could explore how Ichigo's personality remains the same despite the physical change, but she has to adapt to the new social and power - related situations.
Rukia would probably be one of the first to be both shocked and amused. She might tease Ichigo a bit at first but then quickly get serious about helping him. Chad would be very accepting and offer his protection as usual. Uryu might be a bit more skeptical at first, thinking it's some kind of new Hollow trick. Orihime would be very empathetic and try to make Ichigo feel comfortable in his new form, maybe even offer to make some new clothes for him to fit his new body.
One possible plot could be that after all the battles in Bleach, Ichigo discovers a new side of Rangiku and they fall in love. They get married secretly to avoid the chaos it might cause in the Soul Society and the human world. Then they have to face the challenges of hiding their relationship from their friends and families while also dealing with new threats that target them because of their union.
The story could then develop as Ichigo tries to find a way back home. Along the way, he gets caught up in the politics and battles of the DxD world. He might meet Issei and initially be at odds with him because of their different outlooks on power and combat. But as they face common enemies, they start to work together. Ichigo could also have run - ins with powerful devils like Sirzechs Lucifer, who might be intrigued by his power and want to either recruit him or eliminate him as a potential threat.
Perhaps the story could start with Ichigo being experimented on by a rogue group of scientists or powerful Hollows. They accidentally turn him into a female Arrancar. Ichigo then has to adapt to her new physical form. She might discover new abilities that are unique to female Arrancars, like a different type of Cero or Sonido. Along the way, she could make new allies among the Arrancars who see her as an opportunity for change, and she tries to use her new position to bring peace between the warring factions.
The plot could involve a power - sharing concept. Hollowfied Ichigo, with his unique power, might accidentally transfer some of his Hollow energy to Tier Harribel. This new - found power could either be a boon or a curse for her. She may struggle to control it at first, and Ichigo would feel responsible for helping her. This could lead to a journey of self - discovery for both of them as they learn more about each other's powers and themselves.
The plot could involve Ichigo's unique abilities causing a stir in the Highschool DxD world. Since he has the power of Mugetsu, he could be a target for some groups who want to either use his power or get rid of him. And at the same time, he could befriend some of the characters from DxD and they could learn from each other's powers.
Perhaps in the 'ichigo travels back in time bleach fanfiction', Ichigo travels back to the time when the Soul Society was in a more fragile state. He could use his knowledge from the future to help strengthen the Soul Society against upcoming threats, like Aizen's plans. He might train the younger versions of the Soul Reapers and form new alliances that would change the future battles.
Well, one possible plot could be that Ichigo, being born a girl, faces different challenges in the world she's in. Maybe she has to deal with different social expectations compared to if she were male. For example, in a fighting or action - oriented setting, she might initially be underestimated but then prove everyone wrong with her skills and determination.
Perhaps the fullbringers are being controlled by a new, unseen enemy. This enemy wants Ichigo out of the picture, so they use the fullbringers to brainwash him. Ichigo, while brainwashed, starts to cause destruction in the Soul Society. His actions draw the attention of the Soul Reapers, who are initially unaware that he's been brainwashed. As the story progresses, some of the more perceptive Soul Reapers figure out what's going on. They then team up with Ichigo's friends from Karakura Town to find a solution. This could involve a lot of exploration of Ichigo's mind and his past relationships to find the key to breaking the brainwashing.