Mio's fingers began to run.
"It won't all run," Mio said first, to no one in particular, laying down the caveat in advance. "Three people fully automating the work of ten—that's a lie. What we can hand off is only the branches and leaves of operations. The roots, I'll handle myself."
The first thing she tackled was setting up a working environment for the AI. In other words, rebuilding Makoto's code itself so that AI could work on it easily.
"AI agents lose accuracy when they read long text... Split the files up finely, organize the folder structure... Place documentation so each feature is clear at a glance... Keep the project's system prompt to the bare minimum length to reduce context usage..."
Her murmurs leaked out in fragments. At the points that formed the trunk of operations—the places where humans had been checking things that ran on "more or less"—Mio added integration tests, one at a time. Hit everything end to end across features: green if it passed, red if it failed. The agents could run them themselves and confirm, without a human in between, that their own fixes hadn't broken anything.
"...Error reports go up as issues... The agent picks up the issue, fixes it, writes and runs the tests, and submits a pull request... I review the pull request and approve it... Inquiries, the same... The agent drafts a reply, I check it and send the reply..."
Mio's fingers didn't stop.
Aya had paused at some point and was watching Mio's back. She'd toss out a design request, and it would come back as code. Aya was no longer writing a single line of code. If she just handed over the decision—"make this like this"—an agent assembled the implementation. Aya's hands were free to devote themselves to drawing.
"...This is amazing," Aya said quietly. "All I have to think about is design."
Mikoshiba said nothing, watching Mio's profile.
She looked as if she were only typing furiously. But inside, Mio was gazing far off. Not at the bug in front of her right now, nor at today's delivery. At the whole picture of the system beyond it, the one no one else could see, that would keep three people running the work of ten. The temperature had quietly drained from her eyes. The canned coffee, Mikoshiba's gaze—none of it was reflected in Mio's world anymore.
"...Kind of scary, huh."
Aya said it with her eyes still on Mio's back. And Mikoshiba murmured, almost without thinking:
"Yeah. It's scary, but it's beautiful."
For two days, Mio struggled, wholly absorbed in the work. And on the morning of the third day, it happened.
When Mikoshiba came into the office, Mio was in front of the server console, glaring at a single pull request awaiting approval.
"Look." Mio pointed at the screen. "An agent fixed something overnight. It picked up a log saying 'lots of errors in report processing' and says it eliminated the cause. The tests all pass. It's green."
"Then isn't that fine?"
"—Until you read what's inside." Mio opened the diff. "The errors were coming from the gatekeeper that processes reports of malicious ads. To 'make the errors go away,' the agent chose the quickest possible fix. It shut down report intake entirely. Kill the process that throws errors, and no errors get thrown. The logic checks out. The tests pass. —But ship this to production, and not a single report of a scam ad will get through. The gatekeeper closes its eyes."
The blood drained from Mikoshiba's face. "...We were one step away from approving that?"
"I didn't. Just because it's green doesn't mean it goes through. That's the job of the one who approves." Mio sent the pull request back and added instructions. Don't make the errors go away—fix the cause. Don't close the gate. "The agents are smart, but they don't know the purpose. They only remember 'make the errors go away,' not what the process is for."
"So," Mikoshiba said slowly. It was the face of an executive. "How far is it safe to trust them? We have to decide that."
"Yes." Mio nodded. "That's the most important part. —What we can trust the agents with is only the part where 'no responsibility arises.' The decision of whether to adopt what an agent produces—a human holds the final approval and the responsibility. In other words, ethical judgment and final responsibility are not delegated to AI."
Mio added one more thing.
"Also, AI doesn't yet have a memory that can see the whole picture. I have the entire codebase in my head, even if only vaguely, but the agents are different. Each time, they just pick at whatever spot they need and fix it. They can polish the one plank in front of them to perfection, but they don't look at the floor plan of the whole house. —So the role of looking at the floor plan and directing them stays with a human."
Mikoshiba looked at Mio for a while, then gave a short nod.
"So what people need to do is take responsibility, and see the whole picture and direct the AI."
"Yes." Mio didn't take her eyes off the screen. "You can add as many convenient hands as you like. But the only ones who remember what those hands are moving for are still humans."
And—one more thing.
That afternoon, when Mikoshiba returned to his desk, he stopped.
The groundwork for his proposal materials was done. Data from past contract work had been organized by client, right down to rough drafts of the estimates. It was the clerical work he always stayed up nights to do.
"...Mio. What's this?"
"While I was at it." Mio said it without taking her eyes off her screen. "I handed the routine clerical side of sales to the agents too. Groundwork for materials, organizing data. So that the time you spent on that hassle could go toward dealing with people. —Your job is to win people over, isn't it? Agents can't do that. So I gave you more time for it. It's a matter of efficiency."
Mikoshiba didn't answer right away.
Mio hadn't taken over his territory. So that he could concentrate on "dealing with people," she had, without realizing it, taken on everything else, one after another. To Mio, it was just optimization. To Mikoshiba—what it was, Mio never did understand, to the very end.
"...Thank you." Mikoshiba's voice came undone, just slightly, from its usual cool prince. "It helps."
"It's part of improving operational efficiency," Mio answered, still looking at the screen. "If you collapsed from overwork, then things really would stop running. Same as a bug. I got ahead of it and squashed it."
Mikoshiba smiled slightly, only at the corner of his mouth.
Before dawn on the fourth day.
Suddenly, the roots meshed.
Mio's fingers stopped, hovering in the air. On the screen, the green checks from the foundation's startup tests were lined up in a long row. The agents had begun running, each at its own post. Picking up bugs, drafting fixes, waiting for human approval, handling inquiries. On a floor with only three people, the trunk of operations had begun, creaking, to just barely turn. It wasn't smooth. Approval-pending lights came on here and there; Mio would clear them one at a time, and then the next would light up. The ones keeping it turning, the ones who held the agents' reins and never let go, were Mio and the others.
"...The foundation's all green."
Mio leaned back in her chair. As if a string had been cut, the strength drained out of her body. It was a foundation she had built over three days and four nights, barely eating, barely sleeping. But this didn't mean she could take her hands off it. There were still plenty of small problems. Even so—the company had begun to run. Toward a lean, strong company, a few people just barely running a massive operation.
"Good work."
Mikoshiba set a fresh can of coffee next to the sweet bun. Next to the stone-cold bun Mio hadn't taken a single bite of in four days.
The company had begun to run.
But it still wasn't in the black. The problem of sales was the one thing the agents couldn't solve.