Character development often comes from experiencing life from the other's perspective. Harry in Severus' body might become more empathetic towards Severus' cold exterior, realizing it was a shield for his pain. He could develop a new sense of respect for Severus' knowledge.
I think Iron Man and Hulk would be a really interesting pair. Just imagine Tony Stark's brilliant mind trapped in the Hulk's huge, rage - filled body. He would be constantly trying to find a way to control the Hulk's strength and not go on a rampage. And Hulk in Tony's body would be so confused by all the technology and might accidentally set off some of Stark's weapons.
Well, it's really interesting. When Draco and Hermione switch bodies, it's not just about the physical change. Their relationship is affected on multiple levels. Emotionally, they start to empathize with each other. Intellectually, they learn from the way the other approaches problems. Socially, they see how the other is treated in their respective social circles. All these factors combined lead to a significant shift in their relationship. For instance, in some stories, this experience makes them realize that their previous animosity was based on misunderstandings, and they begin to work towards a more positive relationship.
Batman in Catwoman's body would likely be very cautious at first. He's used to his own physical strength and abilities, and now he has to adjust to Catwoman's more agile and stealth - based skills. He might also struggle with the more flirty and carefree attitude that Catwoman often portrays. As for Catwoman in Batman's body, she would have to deal with the serious and brooding nature of Batman, which could be a big change from her own personality.
There could be a scientific experiment gone wrong. For example, they are in a lab for some school project on teleportation or something similar. But instead of teleporting, their minds or consciousness get transferred to each other's bodies. Another way could be through some kind of alien technology. An alien device that was meant for something else malfunctions and causes their bodies to switch.
It could end with them finding a way to reverse the body switch, like by finding another magical item or fixing the scientific experiment that caused it in the first place.
Well, if Deku was in Todoroki's body, his training would be a lot different. Deku is used to his own body's limitations and the way his quirk works in it. In Todoroki's body, he would have to get used to Todoroki's balance of fire and ice powers. He might initially struggle with the dual - natured quirk as it's very different from his own. On the other hand, if Todoroki was in Deku's body, he would have to deal with Deku's lack of natural power control at first. Deku has had to train hard to master his quirk, and Todoroki would need to adapt to that different level of starting ability.
There was a young man, Jack, who through a magical spell switched bodies with a girl, Emma. Jack, now in Emma's body, was astonished by the change. He realized that Emma had a very different daily routine. He had to attend ballet classes which he initially thought would be easy but turned out to be quite difficult. As he spent time in her body, he became more empathetic towards the female experience, like the pressure to look a certain way. Eventually, with the help of an old wizard, they switched back.
Their other friends in Gryffindor would be quite shocked. Neville, for instance, might stutter and not know how to react. Luna might have a more calm and accepting reaction. She might say something like 'This is a very interesting turn of events. I wonder what the magical cause could be?' The Weasley family would be especially confused. Molly Weasley might be worried about Ginny's well - being and Arthur Weasley would be trying to figure out how such a strange magical occurrence could have taken place.
One way is to create comical situations around their relationships. Say, the man in the woman's body tries to flirt with his own girlfriend, but does it in a really awkward way that only the woman's body could pull off. And the woman in the man's body has to deal with the man's nerdy friends and ends up making them do girly things like having a tea party. Add in some funny dialogue where they keep accidentally using phrases from their own gender's vocabulary in inappropriate situations.