After defeating Doppelganger Ryoko, the members of Section 6 exited the Hollow together.
As they stepped back into the real world, the guards stationed outside straightened up and bowed in unison. No one asked questions. No one commented on the damage or the lingering Ether fluctuations.
Section 6 acknowledged them with brief nods and continued on.
What the Doppelganger had said inside the Hollow was left unspoken.
There was no need to talk about it.
At some point, their original purpose, keeping a close eye on Tsutsumi Ryoko, had quietly shifted. He was no longer treated as an anomaly that needed constant supervision, but as someone who stood beside them.
And Tsutsumi, in his own way, had accepted that.
Even when the Doppelganger pointed out the hypocrisy of befriending them instead of acting as a Destroyer, it didn't bother him as much as it probably should have. He had already accepted the idea that this was a problem waiting for him in the future.
Sooner or later, he would find a way to deal with this problem that had been haunting him ever since he discovered his true ability.
Back at headquarters, the unpleasant work was left to the adults, specifically Yanagi.
In one corner of the room, Tsutsumi and Soukaku were doing anything but working. Tsutsumi flicked small candies into the air, and Soukaku bounced around eagerly, snapping them out of the air with her mouth before they could hit the floor.
"Hey, that one doesn't count!" Soukaku protested with her cheeks puffed out, already reaching for the next one.
"You missed it," Tsutsumi replied flatly, tossing another candy upward.
At a nearby desk, Harumasa had already checked out entirely, slumped over with his arms crossed and fast asleep. No one bothered waking him.
Miyabi sat a short distance away, quietly eating slices of melon, her ears flicking now and then as she watched the room without really looking at anyone in particular.
Aside from the Bangboos humming softly as they moved about, Yanagi was the only one actually working.
She typed steadily, compiling the mission report with efficiency. Several sections were rewritten or removed entirely, especially anything involving the Doppelganger's dialogue.
The audio logs were edited to show corruption during the critical moments of the battle.
At Miyabi's request.
Yanagi had hesitated when she was first told. Altering official records was not something she liked doing. But when she looked up and saw the expression on her Chief's face, she didn't argue.
She understood.
Section 6 had their own bond with Tsutsumi.
The higher-ups in H.A.N.D. did not.
Miyabi had caught the meaning behind the Doppelganger's final words. She wanted to ask her son about it, directly and privately. But if someone else reached the same conclusion, it would only invite unnecessary attention and trouble.
Trouble aimed at her son.
So she chose the simpler solution.
Remove the source before it could take root.
After some time, Section 6 finally clocked out.
They had dinner together as usual, nothing special, just a shared table, tired conversations, and food that tasted better after a long day. When it was over, everyone gradually went their own way, splitting off at familiar corners and returning home.
Eventually, it was just Miyabi and Tsutsumi inside their house.
"Ryoko…" Miyabi spoke once she was sure they were alone, her voice low but steady. This was the kind of question that needed privacy. "Are you… some kind of dimensional traveler?"
She had thought about it for a long time.
The him before and the him after she adopted him were like two completely different people. There were too many things that didn't line up. Being unable to use or consume Ether unless evolved to use it. Having too many skills and experience for someone his age. His somewhat otherworldly abilities, combined with the history of heroes that didn't exist in any recorded history.
And finally, the words spoken by the Doppelganger.
Taken together, the answer became obvious.
Tsutsumi Ryoko wasn't from this world.
That explained his lack of common knowledge, things even kindergarteners knew. It explained why his powers didn't follow established logic. It explained why reality itself seemed to bend slightly around him.
Tsutsumi met Miyabi's red eyes and held her gaze for a moment.
"You could say that," he replied.
His voice was calm, steady. His heartbeat was not.
He lifted one hand slightly.
An Aurora Curtain unfolded behind him, its surface shimmering like light on glass. The reflection shifted, forming a window into another world. A peaceful one, cities built alongside nature, humans living together with strange, special creatures.
Miyabi noticed a small, yellow, chubby mouse with a lightning-shaped tail scampering across the screen.
The reflection changed again.
A modern city, partially ruined, shook as a massive black lizard clashed with an equally massive gorilla. Buildings crumbled in the background as the two titans fought without restraint.
Then it shifted once more.
A lone man in a green bodysuit stood his ground against a group of monsters. His silver, bug-themed helmet gleamed under the light, a red scarf trailing behind him as he fought.
Miyabi stared. That figure looked exactly like the first Kamen Rider Tsutsumi had once described to her.
This last window made Tsutsumi snap his head back slightly. He hadn't intended to open anything specific, just random worlds. Accidentally opening one with another Rider was unexpected.
He made a quiet mental note of it.
Lowering his hand, the Aurora Curtain faded away, and Tsutsumi looked back at his mom.
"These are called Aurora Curtains," he said simply. "They're basically windows to other worlds… and I use them to travel between worlds."
The words lingered between them, hanging in the air a little longer than they should have.
For a moment, neither of them spoke.
He could have lied.
He had done it before, more times than he cared to count. By leaving things out. By giving half-answers. By letting people draw the wrong conclusions and never correcting them. It was safer that way. Easier. Lies created distance, and distance meant fewer people got hurt.
But he didn't want to lie to her.
Not about this.
Not when it came to her.
He wanted this, whatever this was between them, to be real. The warmth in her voice when she called his name. The quiet concern she showed without ever making a show of it. The way she treated him like he belonged there, like his presence mattered.
He didn't want any of it to rest on borrowed time or a fragile illusion.
So he continued.
"My name is Tsutsumi Ryoko," he said, his voice steady despite the weight pressing against his chest. "I'm also known as… Kamen Rider Decade."
He paused, drawing in a slow breath.
"The Destroyer of Worlds."
He didn't stop.
He told her everything. He told her the truth about who he really was. His inevitable destiny is to destroy everything and connect everything.
He didn't hold back, telling his mom about how he would eventually turn into the Destroyer of Worlds. How his existence would eventually cause all the worlds to merge together, causing the destruction of all worlds.
Until nothing remained.
And finally, he told her that the only way to stop it.
The only way to prevent the destruction of all worlds…
Was for Decade to die.
He didn't soften the truth.
He didn't try to justify it, or dress it up as something noble. There were no excuses in his voice, no attempt to make himself sound like a hero or a martyr.
This was simply what he was.
If she turned against him after this, if fear replaced warmth in her eyes, if hatred or disgust followed, he would accept it. If she chose to see him as a monster or a threat that needed to be dealt with, he wouldn't retaliate.
He had already made peace with that possibility.
What mattered to him was this moment.
Before any of that.
Before destiny, before destruction, before the name Decade outweighed everything else.
At the very least, he wanted to know one thing for certain. That once, honestly, without lies or omissions, they had seen each other as family.
He exhales slowly, as if releasing something he had been holding onto for far too long.
"And that…" he says quietly, lifting his eyes to meet hers, "is all that I am."
Miyabi listens to him in silence, her expression calm on the surface, yet her heart feels anything but. Inside, her thoughts tangle into something heavy and painful, emotions she can't neatly sort through.
When Tsutsumi first confirmed that he was a dimensional traveler, someone who could walk freely between worlds, her mind had immediately gone to a single, desperate hope.
If he could cross worlds… then maybe he could save them.
Maybe he could bring everyone in New Eridu somewhere else. Somewhere untouched. Somewhere that wasn't slowly collapsing in on itself. Leave this old, dying world behind and start over.
For a brief moment, that thought had almost felt like relief.
But as Tsutsumi continued to speak, explaining what his existence truly meant, Miyabi quietly abandoned that idea. Each word stripped that hope away piece by piece, until nothing was left. Her face slowly drained of color, her lips pressing together as if holding back something fragile.
And when he finally revealed the truth, how the only way to stop all worlds from merging was for Decade to die, her expression didn't shatter.
It became complicated. Too complicated.
To put it simply, as he continued to grow and eventually became Decade, all worlds would begin to merge into one another. A collapse on a scale beyond comprehension. The destruction of everything.
And when he died, those worlds would separate again, some returning to what they once were, others becoming entirely new worlds born from the remnants.
Which meant…
As long as he existed, the end was inevitable.
And when he died, everything would be saved.
Miyabi opens her mouth, wanting to say something. Anything. But no sound comes out. Her thoughts refuse to settle into a clear shape, her feelings pulling her in opposite directions.
If she let things continue as they were, her son would one day become Decade. The worlds would begin to collapse. He would be hunted. Feared. Hated. Until either he was killed… or everything was destroyed.
But if she acted now, if she drew her blade and cut him down before he ever reached that point, she could prevent the catastrophe entirely.
She could save countless lives.
At the cost of killing her own son.
No matter which path she chose, something inside her would break beyond repair.
Let him live, and watch the world march toward doomsday, dragging innocent lives with it.
Or draw her blade… and strike down the child who once looked up at her and called her Mom.
"I'm sorry for making you go through this difficult choice."
Tsutsumi's voice snaps her out of her spiraling thoughts.
This was the first time he had ever gathered the courage to tell someone the truth about his existence. The first time he had allowed himself to be honest.
And all it had done was burden her with an impossible decision.
Miyabi tries to respond, but once again, her words fail her. Her throat tightens, refusing to let anything through. Almost unconsciously, her grip tightens around the handle of Tailless.
She doesn't move to attack. But Tsutsumi can see it. The truth has shaken her deeply.
He understands her dilemma all too well. Kill her son to save countless lives… or let the world end so that he might live.
Slowly, Tsutsumi pulls out a card. He looks at her then, giving her a small, sad smile, one that holds acceptance rather than fear.
"Looks like this is goodbye, Mom."
Before Miyabi can react.
Attack Ride: Time Vent!
The world twisted, and time shifted.
And suddenly, she's sitting in her seat in Section 6, a plate of melon slices resting in front of her.
Her eyes shift to the corner of the room. Tsutsumi is there, casually tossing candies into the air while Soukaku hops around excitedly, catching them in her mouth with enthusiasm.
Miyabi blinks. Something feels… wrong.
Her vision blurs, and she realizes belatedly that tears are streaming down her face. She quickly raises her sleeve, wiping them away in confusion. As she tries to remember why she's crying, what caused it, her mind comes up blank.
There's no answer. No memory. Only a faint ache she can't explain.
She picks up a slice of melon and takes a bite. The juice runs down her fingers, sweet and refreshing.
Yet somehow… It doesn't taste as good as it did before.
"Tsutsumi, where are you going?" Soukaku asks, tilting her head as she notices him stop.
"I'm going out for a run," Tsutsumi replies calmly, standing up and heading toward the entrance.
He pauses at the doorframe.
Then, slowly, he turns back and looks at everyone in Section 6, taking in their faces, their voices, their warmth, one last time. He smiled, snapping a picture of all of them using his camera.
"Take care, everyone," he says softly. Then his gaze lingers on Miyabi. "You too, Mom."
Confusion spreads through the room at his words. Before anyone can question him or make sense of what he meant, Tsutsumi steps forward.
An Aurora Curtain opens quietly before him. And without anyone noticing, he vanished.