zeta
: How to use it, features, and the business problems it solves
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What is zeta?
An "AI fiction" app from Scatterlab (Scatter Lab, Inc.) of South Korea. Choose AI characters or plots (story setups) made by users and advance the story through roleplay conversations. You can also create and publish characters and generate illustrations of conversation scenes. Basic play is free (with ads); zeta pass costs ¥1,650/month, a 1-day pass ¥300, and Pieces start at 200 for ¥300 (App Store prices). For users aged 14 and older.
Business problems it solves
About "zeta"
What is zeta?
zeta is an AI character roleplay chat app operated by Scatterlab (Scatter Lab, Inc.) of South Korea. The company calls it an "AI fiction platform": you choose an AI character or a "plot" (a story setup) made by other users and advance your own story through conversation.
According to the official App Store description, there are more than 3 million characters to talk to, spanning a wide range of genres such as childhood friends, otome-style romance, BL and isekai fantasy. Anyone can create and publish characters and plots, and the app has become popular in Japan for enjoying yume shōsetsu (self-insert fiction) and narikiri (in-character) chats. It is available as iOS / Android apps and on the web (zeta-ai.io), with Japanese support.
According to the company's announcement (May 22, 2026, PR TIMES), zeta has more than 2 million cumulative registered users and more than 750,000 weekly active users in Japan, and in April 2026 it ranked first among Japanese entertainment apps by total usage time.
zeta is for users aged 14 and older. The Terms of Service state that users under 14 may not use the service (the App Store age rating is 13+). Minors generally need a parent's or guardian's consent to use paid services.
How to use
- Install the app and sign up Get the app from the App Store or Google Play, or open the web version (zeta-ai.io), and sign up.
- Find characters and plots Pick a character or plot from the "Trending", "Best" and "New" rankings on the home screen, genre tabs, or a hashtag search.
- Advance the story through conversation Tap "Start talking" and the conversation begins from the scene the creator set up. You can regenerate replies you don't like, edit or delete messages, and use "Suggested replies" when you're not sure what to say.
- Create your own Enter a name, personality, speaking style and background to create an original character or plot—"done in one minute," according to the App Store description. Register your world's lore and terms in the "lorebook," and they are passed to the AI whenever a keyword comes up.
Features
01Play through conversation
- Roleplay chat — Besides one-on-one chats with a character, there are plots with multiple characters and RPG-style plots where only the world is defined
- Memory — Characters remember what you talked about and what you like, and may even message you first on anniversaries (per the App Store description)
- Model selection — In addition to the basic model, you can choose the higher-tier "koji" and "luca" models, which consume Pieces (an in-app item) for each reply
- Styles and plugins — Adjust narration viewpoint (first person, second person, etc.) and story presentation, or use plugins that display information at the top of the screen. Currently limited to the koji and luca models
02Create and publish
- Creating characters and plots — Set a name, personality, speaking style, example situations, a lorebook and more, then publish. Once a plot is published, it cannot be made private again
- Private plots — Free users can have only one plot that only they can talk to; zeta pass makes this unlimited
- Snapshots — The AI generates an illustration of a scene based on your conversation (uses Pieces; takes about 15–30 seconds). Violent or sexual content cannot be generated
Source: zeta on the App Store
Pricing
Basic play is free, with ads shown between conversations. For people who want to remove ads or create more, there is the "zeta pass" subscription and an in-app item called "Pieces."
| Item | Price (JPY incl. tax, App Store) | Main benefits |
|---|---|---|
| Free | ¥0 | Basic conversations are free; includes ads; one private plot |
| zeta pass | ¥1,650/month | Removes all ads, 200 bonus Pieces every month, unlimited private character creation, faster replies |
| zeta pass 1-day pass | ¥300 | Try zeta pass benefits for one day (no bonus Pieces) |
| Pieces | 200 for ¥300 to 10,000 for ¥15,000 | Used for conversations with the higher-tier models (koji, luca), generating Snapshots and more |
Prices are based on the in-app purchase listing on the Japanese App Store. The app sometimes offers a first-month discount on zeta pass.
Things to keep in mind
zeta is designed to be absorbing—the company itself announced that average weekly usage during Japan's Golden Week holidays exceeded 27 hours (about 4 hours a day). To enjoy it safely, keep the following points from the official terms and policies in mind.
01Overuse and spending
- Screen time — Setting your own daily time limit helps
- Pieces are non-refundable — Purchases cannot be refunded for personal reasons. If a Snapshot generation is interrupted because the conversation changed, the Pieces used are not returned
- Purchases by minors — Paid-service contracts by minors generally require a parent's or guardian's consent, and contracts made without it can be cancelled by the guardian
02Personal information and conversations
- Conversations are used for improvement — The privacy policy states that conversation content you enter (text, images, audio, etc.) is used to improve the dialogue algorithms and develop new services. Pseudonymized usage records are kept for five years to improve the AI dialogue algorithms
- Outside AI providers and overseas transfers — Processing such as response generation is outsourced to providers including OpenAI, Anthropic and Google. Data is transferred to South Korea, where the company is headquartered, as well as to the US and other countries
- Don't share sensitive information — If you enter sensitive personal information such as medical history or sexual orientation in a conversation, you are treated as having consented to its use. Avoid entering anything you don't want known
03The nature of AI and safety
- Answers aren't guaranteed to be accurate — The Terms of Service state that the accuracy of AI characters' responses is not guaranteed. Enjoy what characters say as fiction
- Prohibited uses — Creating plots that inappropriately objectify minors and deliberately circumventing safeguards are prohibited by the terms
- When things are hard — If words related to suicide come up in a conversation, the app shows a message pointing you to sources of support
Pros and cons
Pros
- Choose from more than 3 million characters across a wide range of genres
- Basic conversations are free, with plenty of Japanese-language characters and plots
- Create and publish your own characters and worlds for other users to play
Cons
- The free version shows ads, and the higher-tier models and illustration generation require Pieces
- In long conversations, characters may forget earlier details or go off-script (a frequent point in App Store reviews)
- Conversation content is used to improve the service, and processing is outsourced to overseas providers
Reviews and reputation
On the Japanese App Store, zeta is rated 4.5 out of 5 from 190,000 ratings and ranks No. 2 in Entertainment (as of October 2026). Reviewers enjoy the feeling of "building a story together with AI" using distinctive characters and plots made by other users, while others complain that it forgets earlier content in long conversations, that updates have tightened content restrictions, and about price changes for the higher-tier models.
FAQ
Q. Is zeta free? A. Basic play is free, with ads between conversations. To remove ads you need zeta pass (¥1,650/month) or a 1-day pass (¥300); the higher-tier models and Snapshots require Pieces.
Q. What is the minimum age? A. The Terms of Service require users to be 14 or older. Accounts found to belong to users under 14 may be deleted.
Q. How do I cancel zeta pass? A. At least 24 hours before the next renewal date, cancel from App Store subscriptions on iPhone, Google Play subscriptions on Android, or subscription management in your account settings on the web. The company does not process cancellations itself.
Q. Who operates zeta? A. Scatterlab (Scatter Lab, Inc.; CEO Kim Jongyoon) in Seoul, South Korea. Its notation under Japan's Specified Commercial Transactions Act is published on the official site.
How it differs from Character.AI and other AI character chats
| Service | Highlights | Pricing model |
|---|---|---|
| zeta | Operated by Scatterlab (South Korea). Rich in Japanese characters and plots; storytelling geared to self-insert fiction and in-character chat. Ages 14+ | Free (with ads) + zeta pass and Pieces |
| Character.AI | Operated by Character Technologies (US). One of the largest character libraries in the world, voice calls. Chat limited to users verified as 18+ | Free (unlimited) + monthly plans |
| Chacha（旧Anirole） | A creative community combining chat with anime-style illustration generation, oriented toward mature audiences | USD-based diamonds |
| Cotomo | Developed by Starley (Japan). A voice chat app with a single conversation partner who remembers your talks | Free + pay-as-you-go |
If you want roleplay that feels like reading and writing a story in Japanese, zeta is the pick; to explore a broader, English-heavy character library or talk by voice, compare Character.AI. If you want to write a novel itself, a writing tool like NovelShaft is a better fit.
The information on this page is based on zeta's official site (Terms of Service, Privacy Policy and Specified Commercial Transactions Act notation), the Japanese App Store listing, and the company's press release as of October 2026. Please check the official site for the latest features and pricing.
