YOUR OC and MY OC are at a masquerade party. variations of the scenario can be:
i.a, the enemies to lovers: YOUR OC and MY OC are rivals and usually heavily dislike each other due to external factors (academic rivals, family feuds, etc) and so they don't really get the chance to get to know each other. but during the masquerade, they don't recognize each other, and start talking.
i.b, the cinderella scenario: YOUR OC and MY OC have never interacted with each other before. they might know each other (one might be a servant for the other, they might be coworkers, etc), but during the masquerade, they ended up enjoying each other's company. but they forgot to take their masks off and reveal themselves, and so now they have to figure out who the other person from the party was.
