After traveling the outside world, Kozuki Oden returned to Wano Country and learned about Kurozumi Orochi's actions as the shogun in his absence. Oden tried to strike him down, but Orochi was well protected and backed up by Kaidou. Orochi and Kaidou offered Oden a deal, which they promised to be paid off in five years time, and Oden agreed.
Five years later, Oden met with Orochi and learned that the latter never intended to fulfill his part of the deal. Angered, he gathered his men to battle Kaidou.
Due to their image of walking past the setting sun on their way to face Kaidou, Oden's retainers were named the Nine Red Scabbards (赤鞘九人男,Akazaya Kunin Otoko?).
On their way to Onigashima, they came across Kaidou and the Beasts Pirates in Udon, and a massive battle broke out, which resulted in Oden's defeat and imprisonment.
Kaidou: They will speak of you for years to come saying that you died a spectacular death. Oden: They can forget me, for all I care. My soul will live on!!
For their crimes against the shogunate, Oden and his men were sentenced to be executed by being boiled alive. At the time of the execution, a crowd gathered around the execution site where a large pot filled with boiling oil was placed. After being escorted to the pot, Oden then stopped and turned to face Orochi and Kaidou, who sat in a nearby stage. He asked to have a time limit, after which those who survive can walk free. Belittling that chance, Kaidou agreed and gave the men an hour. Oden then entered the pot, and as his men rushed to join him, he held up a platform and ordered them to stand on it, saving them from entering the boiling oil.
Mere minutes after the execution started, the crowd began to complain about Oden taking too long to die, causing Shinobu to lash out at them, revealing the truth behind Oden's deal with Orochi, and the shogun's corrupted goals. As the people listen in disbelief, Fukurokuju arrested Shinobu, before some of the watchers asked Orochi to stop the execution, but were shot with arrows. Realizing they were surrounded by Orochi's men, they spread the story to the rest of Wano.
As the hour continued, Oden was encouraged by the citizens, and talked to his retainers about his wish to open Wano to the rest of the world, knowing that this was his last day, leaving the task to them.
After an hour of torture, the people cheered for Oden's triumph, although their celebration was cut short, when a firing squad was assembled and aimed their guns toward Oden and his men, still in the boiling pot.
For I... am a story to accompany your drinks... I am Oden!! And I was born... ...to boil!!!!
— Kozuki Oden's final words, completed by the people of Wano.
Orochi then revealed he changed the sentence a minute prior, and a person was gunned down when trying to object.Oden threw his men away from the execution site and told them to run and survive to fulfill his wish. With the firing squad chasing the retainers, Kaidou drew his own pistol and had final words with Oden before executing him with a shot to the head, and as the great samurai's body sank into the boiling oil, the crowd cried for Oden.
Kaidou then went to Oden Castle in Kuri to kill Oden's family, and his crew set the castle on fire. After escaping the execution, some of the retainers fled back to Oden Castle in Kuri only to find the place aflame. Inside, they found Kozuki Toki holding herchildren. Toki then ordered Kin'emon to take care of Momonosuke as she sent them and few other retainers to the future, as she was asked to do so by Oden. Toki then had Kawamatsu take care of Hiyori, and the two escaped the castle as it was surrounded by enemy forces. Toki herself stayed to deliver a prophecy about the family returning in 20 years time.
Yamato, who witnessed the execution, developed a strong admiration for Oden and aimed to open Wano's borders. She also acquired his journal and kept it to herself.
This event might be a reference to one version of the execution of Ishikawa Goemon, who was also sentenced to death by boiling, that says that he was boiled alive in an iron cauldron along with his son, whom he held above his head. However, neither survived.
In Chapter 973, a waning crescent moon was shown, implying that Oden's death occurred at the end of the month.