Summer 2026 anime Mushoku Tensei III ～Isekai Ittara Honki Dasu～ aired its twelfth episode, titled “Owari to Hajimari” (End and Beginning), on 13 September 2026 at 24:00. Fans who had read the source novel had been warning others that “the next episode is going to be hell” — and they were not wrong.

About the Series

Mushoku Tensei ～Isekai Ittara Honki Dasu～ is based on the web novel by Rifujin na Magonote, serialised on Shōsetsuka ni Narō since 2012. It follows a 34-year-old shut-in who is reincarnated in a fantasy world as the boy Rudeus Greyrat, carrying his past-life memories and determined to live his new life to the fullest. Season 1 aired in January 2021; Season 2 followed in 2023, covering the “Quagmire,” “Ranoa Magic University,” and “Teleportation Labyrinth” arcs. Season 3, which began on 5 July 2026, opened with the “Eris Training” arc and has since moved into the new “Chaos Breaker” arc featuring the Dragon Armour King Perugius.

A Mysterious Old Man from the Future

Episode 12 picks up immediately where the previous episode left off: Rudeus (CV: Uchiyama Yumi) faces the mysterious elderly stranger who appeared at the end of episode 11. The old man reveals himself bluntly — “I am you, roughly fifty years from now.” He knows Rudeus’s name from his previous life and tells him, “I know this sounds like a Hollywood movie, but we really don’t have time” — a curious reference in a world where Hollywood does not exist, which only makes his claim more convincing.

The Bombshell: Roxie Will Die

The old man explains why he stopped Rudeus from entering the basement in episode 11, and the reason is staggering:

“A few weeks after you go down to that basement, Roxie dies.”

The cause is almost absurdly mundane. A sick rat in the basement had gnawed on leftover food. Roxie, feeling peckish late at night, snacked on those very leftovers — and became infected. The disease is called Majin-seki-byō (Magic Stone Disease), a fatal illness that gradually turns the body into magic stone. Humans rarely contract it, but Roxie has a specific reason that makes her vulnerable.

Online reactions ranged from stunned to darkly comic: “She dies because of a midnight snack?!” “That’s all it takes to justify the warning.” “The bombshell of Roxie dying was just dropped on us out of nowhere.”

Nanohoshi, Sylphiette, and Eris

The old man goes on to warn about the futures of Nanohoshi and Sylphiette, and delivers a stark verdict on the god-like being Hitogami: “Don’t be swayed by his words. He is the root of all evil — the final boss.”

He then turns to Eris, begging Rudeus to write her a letter immediately. Rudeus resists — “She’s the reason I became impotent” — but the old man admits that despite their violent clashes over the years, Eris always helped him from the shadows when he was in danger. He describes her as being “like the prince of the vegetable kingdom” — a line that in the original novel references a famous character from a nationally beloved manga series, here adapted for the anime. Readers of the source material were delighted the line survived intact.

Three Tasks

As the old man’s condition visibly deteriorates, he presses three instructions on Rudeus before collapsing:

• 1) Consult Nanohoshi.
• 2) Write a letter to Eris.
• 3) Be suspicious of Hitogami — but do not make an enemy of him.

He hands over a diary he has kept, and in his final moments uses his “foresight eyes” — a gift from Kishirika — to glimpse Sylphiette and Roxie through the door. Fans were moved: “At least he got to see the two of them one last time.” “The foresight eyes Kishirika gave him made this moment possible — thank you, Kishirika.”

Rudeus opens his door to find Sylphiette and Roxie asking if someone was there. He deflects their concern, asks both of them to stay in their rooms for the night, then heads down to the basement to confirm the rat’s existence before sitting down to read the diary.

Sugita Tomokazu as Old Rudeus

The role of the elderly future Rudeus is played by Sugita Tomokazu, who has voiced Rudeus’s “past-life self” throughout the series. His performance in this almost entirely dialogue-driven episode drew an outpouring of praise:

• “Sugita’s acting was on another level entirely.”
• “The episode felt like it was over in seconds — I was completely absorbed.”
• “You could feel in both the animation and his voice just how little time he had left.”
• “His anguished delivery had me in tears.”

Sugita also hosts the web radio programme Mushoku Tensei III: Kokoro no Koe Radio on the TOHO animation YouTube channel.

Looking Ahead — Episode 13: “Diary”

The next episode is titled “Nikki” (Diary). Readers of the source novel are already bracing themselves: “Just seeing the blood-stained cover tells you everything about what’s inside.” “If this week was this shocking, what on earth is next week going to be?” “This is where the real hell begins.”

Broadcast Information

Mushoku Tensei III ～Isekai Ittara Honki Dasu～ airs every Sunday at 24:00 on TOKYO MX and BS11; 24:45 on KBS Kyoto; 25:30 on Sun TV; and every Tuesday at 22:30 on AT-X. Simultaneous streaming is available on ABEMA and dAnime Store from Sunday at 24:00.