Well, my favourite twins are the Hitachiin twins, but they're already posted. My 下一个 favourite are the Asaba twins, but there also posted. So I'll post my third favourite. Hope it counts! Ta-da!!!
Yuki and Kanade from 糖果 Boy.They're often referred to as twins but they have different birthstones. They're the same age too but the lighter haired one is technically older x3