The camera fades in on a bright blue sky. A single black feather drifts into view, and the camera follows it down to the ground as it lands on a grassy field. The feather is then promptly blown away by a familiar green pointed shoe hurrying along.
Wario, in his traditional cap and overalls, is hot on the trail of his biggest score yet. As he runs along, he rudely shoves aside a Shy Guy as he turns a corner, and takes out a diving Flaptor without even taking his eyes off his treasure map. Speaking of which, the camera cuts to Wario's point of view, showing the map leading to a treasure chest spilling with riches. And what luck, for the map is pulled down to reveal the exact same treasure chest in front of him!
"Yahoo!" cries an elated Wario, as he puts away the map and makes a beeline for the chest. He pulls open its lid, its contents glowing. There's a close-up on Wario's face, practically drooling with anticipation.
It's a huge (and I do mean huge) diamond, with two innocent eyes.
Wario wastes no time in plucking the diamond out of the chest and holding it up to the light to examine it. As he laughs heartily over his victory, a beak plucks it out of his hand, its owner just off screen.
It takes Wario a couple moments to realize the theft, and when he does, he's furious. The camera pans up to reveal a giant black bird wearing a Power Star necklace, the gem in its clutches. It gives Wario a knowing look before flying off.
But Wario is having none of it, no sir! He leaps after the bird and clings onto its neck, intending to give it what for. The bird shrieks in surprise and drops the gem, prompting Wario to leap down after it.
He... doesn't exactly stick the landing, falling with his face in the dirt. The gem bounces off and rolls away, stopping at someone's red shoes. The figure picks up the diamond just as Wario gets back on his feet. He sees the stranger with his treasure and shouts in anger, challenging them to a fight. In response, the newcomer puts away the diamond and adjusts their headlamp, just as the camera pans to reveal...
Captain Toad is Ready For Adventure!!
"Fight time!" he declares, brandishing a pickaxe and transitioning into gameplay footage.
During this gameplay footage, Toadette is shown off as an alt, with a tagline I can't think of yet.
The trailer ends with Captain Toad and Toadette sharing a high five. As they do so, the bird from before flies away with another treasure chest in its talons. The Toads yelp in surprise, before heading off after it. And the adventure continues...!