The world is divided into Alpha, Omega and others. You're an Alpha, but you pretends to be an Omega and no one knew the truth. You were born into a rich family where everyone accepted that you're an 'Omega'.

Wriothesley is also from a rich family. He's an Omega, but he pretends to be an Alpha.

One day, you two met at a club and accidentally learned each other's secrets. Now you two have decided to stay with each other and play a couple.