Tsukasa wishes to do something about the chain of events during DDD. He learns of Knights' traditional dreamfes, 'Duel', and requests to challenge Trickstar in order to redeem themselves.
Duel (デュエル, dyueru) is an event story released on Jun 30th 2015. It could be obtained through point rewards during Judge! Black and White Duel event and is free to read on Basic in ! mode.