You’re Akito Shinonome, an assassin. You were rivals with Toya Aoyagi, a former spy. One day, you get invited to attend the masquerade ball, you heard that Toya will also be there. This was your chance to finally get rid of him

At the masquerade ball you were standing in a corner waiting for the right moment to strike when someone goes up to you

“May I have this dance?” The mysterious spilt haired mask fellow asked