WARNING: The following contains spoilers for One Piece Episode 968, "The King of the Pirates is Born! Arriving at the Last Island!" now streaming on Crunchyroll and Funimation.
While exploring the grand line with not one, but two different pirate crews, One Piece's Oden Kozuki has likely never been to the same place twice -- until now. But his return to his homeland in Episode 968, "The King of the Pirates is Born! Arriving at the Last Island!" is nothing like anyone expected or hoped for. It's neither the triumphant return his retainers wanted, nor is it the isolation-ending event Oden himself likely wanted. Instead, he arrives, translates a Ponegliff and is gone again within a few hours -- because if he had stayed any longer, he might have endangered his marriage... and his adventure.
As the last episode revealed that Wano has one of the Road Ponegliffs needed to discover the last island of the Grand Line, the crew of the Oro Jackson are already on their way when Toki, Oden's Wife, suddenly collapses. While Crocus assures Oden that Toki will live, she will only do so if she stops traveling, and since Wano was her original destination, it might be high time she settles down.
Oden, the loving husband he is, while dismayed at this news is perfectly (albeit sadly) willing to stay in Wano and care for her -- but before he even gets the chance to offer, Toki immediately berates him for even thinking about it. After all, the man she fell in love with is an adventurer, explorer and someone who can't stand living in a cramped country like Wano. So instead, she implores him to continue on to the last island with Roger, even going so far as threatening to dissolve their marriage if he doesn't!
Cat Viper and Dogstorm ease this transition by offering to stay in Oden's stead, taking care of Toki and the kids, introducing them to the land and smoothing things over with the other Nine Red Scabbards. All of which leaves Oden with very little choice but to go on.
So when they arrive on the shores of Wano, greeted by the remaining Scabbards, things are understandably difficult for everyone involved. While the Scabbards are overjoyed at Oden's return, they are shocked by the existence of Toki and Oden's kids. Meanwhile, Oden notices that his retainers' clothes now have shoddy patches where once was regal fabric befitting their status -- but before they can explain, Toki, fierce as ever jumps in. She asks the retainers to prove their love for Oden... by letting him go.
So Oden turns his back on his loyal followers and heads back out to sea after translating the Road Ponegliff, much to their dismay and anger (in that order.) But as Oden himself does not look back, we soon find out there's another reason he left so quickly. More than just Toki's threat, Oden sensed something was wrong. His retainers' clothes indicated that they had little money, which probably meant the people had little money. Furthermore, ominous smokestacks littered the skyline, something that made no sense to Oden himself. While we as the audience can infer that these are acting-Shogun Orochi's weapons factories, to Oden, they are nothing more than a mystery that must be ignored.
The reason Oden must ignore all these signs is simple -- his wife's threat was not just about sending him onwards without her, but about his well-being. She fell in love with a carefree man, and if he had stayed with her, she knew he'd be forever looking out to sea and wondering what could have been. Had he stayed any longer, or investigated the smokestacks even a little, Oden's heart would have been drawn to his people and he would be unable to carry on in the carefree way Toki wanted him to. So, for his own good, Oden hardened his heart and forced himself not to look, lest he sees and be compelled to bring justice.