WARNING: The following contains spoilers for One Piece Episode 902: "The Yokozuna Appears! The Invincible Urashima Goes After Okiku!"
In One Piece's previous episode, the villainous Holdem (one of the Shogun's holders, with a separate lion head for a stomach) kidnapped Otama. Holdem's men witnessed Otama pacifying a restless baboon by plucking a piece from her cheek, turning it into food. Holde believes Otama possesses a Devil Fruit ability, and will, if he has to, pluck the flesh off of her face to harness her abilities.
Meanwhile, Luffy and Zoro pursue after Otama to Bakura Town, where the Shogun's fiercest warriors reside. Joining them is the enigmatic samurai Okiku, an extraordinarily tall woman of unknown skill. They break through the gates of the city, with Luffy ready to plow through all adversaries who dare lay a finger on Otama.
Beyond the Gates
Luffy, never one for subtly, loudly declares his intention to save Otama upon walking through the gates. This alerts the attention of everyone in town -- and all of them are in league with Holdem. While Okiku tries to smooth things over, Luffy decides to just knock everyone out.
Luffy does that by radiating his Haki, the Color of the Supreme King, an ability manifested by Luffy's sheer willpower alone. With everyone who heard him enter now unconscious, they travel through town unrestrained. That said, many people seem to notice the three strange characters riding atop a giant monster dog.
Bakura Town had once been a vibrant town filled with townspeople. However, that changed when Orochi arrived and became shogun. Nonessential people were thrown out of town, leaving only those Orochi wanted.
The Sumo Wrestling
Then a sumo wrestler comes flying at them. Luffy catches him before he can hit. It turns out, however, that this wrestler had just been knocked out of the ring by Urashima, the same wrestler who, episodes prior, had flirted with Okiku.
Prior episode, Urashima decided to force Okiku to become his bride. As someone high ranking in society, Urashima figured it was his right to take what he wants. At this point in the episode, however, the towering sumo wrestler manages to swat aside a team of two sumos attempting to bring him down, all without taking a step. This is of course before more sumo wrestlers come, all being sent flying by the sumo.
Luffy, however, just comes to watch the fight, in awe of the display. Okiku recognizes Urashima -- who then recognizes her, thinking he came to watch his performance and to marry him. He loudly declares this, convincing the crowd that they can expect a marriage on top of this tournament.
Because of that excitement, everyone ignores Luffy when he asks for directions to Holdem's lair. When they step down to look for directions, the sumo come to bring Okiku to her "future husband." They try to get Luffy and Zoro out of the way, but find themselves outmatched by the two.
However, a few of the sumo slip around and snatch Okiku. Zoro could have stopped them, but they reminded him how unfair it is to draw his sword on an unarmed man. So Zoro fights with her bare hands. However, even though the sumo carry her off, Zoro doesn't seem worried. After all, she isn't some tea maid, but a legitimate samurai.
When she's brought to the stage, everyone recognizes her as the tea maid, mocking her even as Urashima hears. But, to the massive samurai's credit, she defends Okiku's pride by -- no, that's a lie. He defends his own pride in declaring that, since he's of such high class, everyone is beneath him, so no one in town is any different to him.
He charges in for a kiss ...
An Awkward Marriage Proposal
Only for her to leap out of his way, draw her katana, and carve his topknot off his head with delicate, precise aim. She didn't take too kindly to being called lowly and small by someone who never took into consideration her feelings.
As Zoro points out, this public display is a great way to lure out the boss. But Urashima, humiliated and enraged, rounds on her, ready to pummel her with one smooth strike. While she at first seems horrified, she then comments that Urashima would be the kind of man to hit a woman. This manages to infuriate him more as he charges in for a strike known to send people flying --
So, naturally, Luffy eagerly swoops in, matching Urashima's slap with one of his own. Luffy grins, eagerly, as the episode comes to a close.