Scenario 1: Side A is a villain and side B is a hero. Side A kidnaps side B for (insert reason)

Scenario 2: Side A is a villain and side B is a hero. Side A hate being a villain and wants to join the heroes. Will side B let him?

Scenario 3: Side A is a villain and side B is a hero. Side A is sent to spy on side B and just the heroes in general but ends up falling for him and no longer wants to be a villain. But what happens when side B finds out the truth

Scenario 4: Side A is a villain and side B is a hero. They are both dating, unaware of who the other is and how at night, they are enemies

Scenario 5: Side A is a human dating side B who is a famous hero/ villain but can't tell anyone

Scenario 6: Make it up