User blog comment:Xilinoc/Ch. 571 (Yachiru's gonna wreck it)/@comment-11446176-20140305130913/@comment-11051098-20140306163609

The tsuba was "ordinary" at the time Kenpachi picked up the asauchi from the dead Shinigami. But ever since the moment Unohana first saw him and fought him, his Zanpakutô looked exactly like it does now, with the hilt wrapped in white bandages and the specific tsuba.

The way I see it, his Zanpakutô mostly looks to be in it's sealed state, and he just doesn't know it. But if Kubo have confirmed that his Zanakutô is constantly in its Shikai, then there's nothing more to say.