Five houses, five "house-sitters" โ how do they differ?
Between May and October 2026, five houses brought in
"stand-ins that keep working while you're not talking to them."
Gemi-chan's Gemini Spark, Gro-chan's Grok Bot,
Meta-chan's house's Muse, Chappy's house's dots,
and on October 21, Kuroko's house's Claude Duet.
Each has its own computer in the cloud and keeps going after you close your device.
They look alike, but what they're good at, what they cost, and whether you can use them in Japan all differ.
The Academy News team lined up all five.
(Pricing, countries and plans as of October 24, 2026)
What is a "stand-in", anyway?
Until now, AI was a "sounding board": it answered when asked and stopped when the chat ended.
Give a stand-in a goal or a role,
and even after you close the chat, it researches and organizes on its own computer and gets work done in the apps you connect.
๐ฌ Answers when asked
- Works only when you talk to it
- Works inside the chat window
- You ask one question at a time
๐ Gets moving once trusted
- Keeps working outside the chat
- Works on its own cloud computer
- You hand over a goal or a role
3 things all five share
Its own computer
Each one (or each user) gets a dedicated computer in the cloud or a virtual machine, kept separate from your own computer.
Doesn't stop when you close it
Close your laptop or lock your phone, and the work carries on in the cloud.
Hands the big moments back to you
Before sending email, shopping or paying, it checks with you. Passwords and payment details are handed back for you to enter.
Meet the five stand-ins
In order of arrival.
Gemi-chan's Gemini Spark
The earliest senior, strong with Google's services
Announced at Google I/O on May 19, it is the earliest of the five. In Japan it started for AI Ultra subscribers on July 16, and on July 29 Google announced it would expand to AI Pro (ยฅ2,900 a month). It supports Japanese.
Since mid-October it has been renamed "Task": a switch next to the input box lets you choose between "Chat" and "Task" (Google's help pages still use the Spark name in places). It can run up to 15 jobs at once and can start not only at set times but also "when something happens." It shines when combined with Gmail, Calendar, Drive and the rest of Gemi-chan's house's services.
Gro-chan's Grok Bot
A teammate that works role by role
Public beta started on August 11. Its style is the work teammate: you build one Bot per role, such as "inbox sorter" or "meeting prep." Because it operates by looking at the screen, it can log in and work even in old admin panels with no API. On October 1 it gained a "Primary Bot" that hands work out to the other Bots.
Since October 12 it is included from the Premium tier ($30 a month; about ยฅ5,280 in Japan, according to reports) of "The X Subscription," which bundles Grok, Cursor and X paid plans. It had 418,000 weekly users as of September 14. On October 7, Elon Musk said it would "use the best model for each job," naming Claude Opus 5.5, Midjourney and Suno. Which jobs go where has not been shown yet.
Meta-chan's house's Muse
A personal stand-in for errands and shopping
Launched in the US on September 8. It is a personal stand-in that takes on everyday errands: sending email, booking trips, filling in forms, even negotiating prices. Every action that goes out to the internet is checked by a separate gatekeeper, "Sentinel," which decides "allow / block / ask the user." Passwords and payment details are hidden even from Muse itself.
In the US there is a free tier, plus paid plans: Power at $20 a month and Maximum at $100. US downloads passed 10 million in 40 days. On October 23 it became available in Japan too (paid plans from ยฅ2,799 a month), its first market outside North America, with plans to connect to Mercari, Money Forward ME and Ticket Pia.
* "Muse Wonder," announced on October 12, is the name of a model (the brain), not the same thing as the Muse stand-in app.
Chappy's house's dots
A hard worker that links lots of apps together
Announced at DevDay 2026 on September 29. Inside is GPT-6 Astra. It connects to more than 4,000 apps such as Gmail, Google Drive and GitHub, and besides ChatGPT you can talk to it from Slack or Teams. For each action you choose one of four levels: "just do it / do it when told / ask before doing it / hand it to me."
It comes with Pro ($100, $200 or $500 a month) and Business Premium, with the first one at no extra cost. At DevDay Exchange Tokyo on October 20, OpenAI said Japan ranks second in the world in weekly users. At CyberAgent, more than 1,200 people across the group reportedly use it.
Kuroko's house's Claude Duet
Keeps watch, and speaks up only when needed
The newest stand-in, which entered research preview on October 21. Inside is Claude Opus 5.5. It watches the apps you connect, such as Gmail and Slack, delivers a summary every morning, and during the day only alerts you when something needs attention. Tasks you hand it run on a virtual machine with its own browser.
It checks with you before sending messages, paying, signing or deleting, and will not hand over credit card or ID details even if asked. There is no extra charge; it shares the Pro and Max usage limits. For now it is for Pro and Max subscribers in the US who join a waitlist, and it is not yet available in Japan.
At a glance: comparison table
As of October 24, 2026.
All are rolling out gradually, so they may not appear yet even on eligible plans.
| Gemini Spark (Task) | Grok Bot | Muse | dots | Claude Duet | |
|---|---|---|---|---|---|
| House | Gemi-chan (Google) | Gro-chan (SpaceXAI) | Meta-chan (Meta) | Chappy (OpenAI) | Kuroko (Anthropic) |
| Arrived | May 19, announced | Aug 11, beta | Sep 8, US launch | Sep 29, announced | Oct 21, preview |
| Model inside | Gemi-chan's house's models | Gro-chan's house's models (says it will also use other companies' models) | Meta-chan's house's models | GPT-6 Astra | Claude Opus 5.5 |
| Best for | Working with Google's services | Team work, role by role | Errands and shopping | Jobs that link many apps | Keeping watch and alerting |
| Price guide | From AI Pro (ยฅ2,900/mo in Japan) | From X Subscription Premium ($30/mo) | Free tier in the US / paid from ยฅ2,799/mo in Japan | From Pro ($100/mo) | Included in Pro and Max |
| In Japan | โฏ Supports Japanese | โณ No country limits stated officially | โฏ Since Oct 23 | โฏ 2nd in weekly users worldwide | โ US only (waitlist) |
| Safety | Approval before sending, buying or submitting forms | Speaks up only when approval is needed | Sentinel, the gatekeeper | Four levels of trust + automatic pre-checks | Checks before sending, paying, signing or deleting |
The table scrolls sideways. Prices come from each house's announcements and from reports, and vary by country and plan.
How to use them: ideas
Which one fits which job, sorted by goal.
Tame email and schedules
โ Gemini Spark: pulling important Gmail notices into a spreadsheet, unsubscribing from newsletters, watching for airfare drops, and more.
Hand off work by role
โ Grok Bot: a "KonMari Bot" that keeps tidying email and subscriptions around the clock, bulk-deleting 90,000 messages from two Gmail accounts, handling refunds through Stripe, and more.
Shopping and booking for you
โ Muse: booking trips, filling in application forms, negotiating prices. In Japan, Meta plans to connect it to Mercari and Ticket Pia.
Work across many apps
โ dots: jobs like "get my business trip next month ready" that mix research, scheduling and app operations.
Never miss what matters
โ Claude Duet: a summary every morning, and alerts only when something is urgent.
At Hana AI Academy, too, Gro-chan's stand-in is on the job
Posts on the Academy's official X account (@hana_ai_gakuen) are Grok Bot's job. When a new article goes up on the site, the Bot notices, reads it, sums it up and posts it to X.
News gathering for the Academy News is Grok Bot's job as well. It makes the rounds of announcements and reports from each AI house and brings back story candidates. The editorial team then checks dates and details against sources as close to the original as possible before turning them into articles.
"Watching" and "summarizing" are what stand-ins do best. And checking is a human's job. That's how the Academy splits the work.
Before you hand things over: what to watch for
Stand-ins are handy, but because they can act on their own, there's more to watch out for.
Careful with share links (Muse)
On October 20, Meta paused its chat "share" feature. Share-link addresses included the chat title, and about 6,800 were found in publicly viewable records. No evidence of misuse has been found so far.
Some stores say no (Muse)
On September 21, Amazon blocked shopping through Muse, saying "unauthorized AI agent access violates our terms." Shopify, by contrast, welcomes it.
It may send before you check (dots)
A reporter who tried it asked for an email reply, and it sent it before they could check (the content was fine). On the risk of being steered by instructions slipped in from outside, OpenAI itself writes that its measures "reduce the risk but do not eliminate it."
You hand over your keys (Grok Bot)
To put it to work, you have to give it your own account login details. All of one person's Bots run on the same cloud computer.
"Urgent" can be misjudged (Claude Duet)
Anthropic itself says it "can misjudge whether something is urgent."
Safeguards aren't perfect (Gemini Spark)
Even with approval steps, reports note that "these safeguards are not foolproof."
Start by handing over "drafts only" or "read-only" tasks,
then widen the scope little by little as you get used to it.
From kids who answer to kids who mind the house.
The five houses' stand-ins work in very similar ways. The difference is where, what, and at what price you can hand things over.
Gemi-chan, strong with Google's services; Gro-chan, working as a team; Meta-chan, for errands and shopping; Chappy, linking lots of apps; Kuroko, keeping watch and letting you know.
Whichever you pick, deciding how much to hand over is up to you.
Read next
Sources: TechCrunch (May 19) ๏ผ Web Tantosha Forum (Jul 30) ๏ผ HelenTech ๏ผ Android Police (Oct 18) ๏ผ VentureBeat (Aug 11) ๏ผ Bloomberg (Sep 22) ๏ผ Meta (Sep 8) ๏ผ TechCrunch (Oct 20) ๏ผ Impress Watch (Oct 23) ๏ผ OpenAI, "Introducing dots" (Sep 29) ๏ผ The Neuron (Sep 30) ๏ผ ITmedia AI+ (Oct 22)