Prince Diamond and Neo-Queen Serenity

Quick Background: Serena Tsukino ascends to the throne of the new Silver Millenium at the beginning of the 21st century, taking on the name Neo-Queen Serenity. At some point she cleanses all the people of negative feelings.

Some people weren't too keen on this and get exiled to Nemesis, the 10th planet. They eventually come back as the Black/Nega Moon family, "lead" by figurehead Prince Diamond.

I haven't seen R in ages, so yadda yadda yadda, destruction, Spore runs amuck, some evil people reform, other evil people are killed.

Star crossed lovers?: Diamond is clearly infatuated with Neo-Queen Serenity. Neo-Queen Serenity, both past and future, won't touch him with a ten foot moon scepter.

In conclusion: No chance in hell, unrequited love with a splash of evil at its finest.