Ninkki - Personal AI Diary
Go viral with AI followers
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
"What if thoughtful AI readers responded to your private journal?"
Ninkki is a private AI diary app. AI characters (clearly labeled as AI) leave supportive reactions, comments, and reflections on your personal entries — like a warm circle of readers who exist only for you.
This is NOT a social network. Your diary entries are private. AI reactions are fictional and generated in real time by the app.
--- What You Can Do with Ninkki ---
■ AI Readers Respond to Your Diary
Write about your day in text or images. AI characters leave reactions that are always clearly labeled as AI-generated. Your entries are private to you.
■ Personal Writing Analytics
AI analyzes your writing style — patterns, word choice, emotional tone. Discover your unique "writing personality."
■ Collect Badges
Earn over 30 badges tied to your journaling habits.
■ Optional Private Sharing with Close Friends
You may invite real close friends via QR code or link to read each other's entries in a closed, opt-in, private group. There is no public sharing feature.
■ Calendar Journal View
Look back on past entries in a familiar calendar layout.
--- Three Plans (AI Reader Capacity) ---
Free Plan
A small circle of AI readers. 3 entries/day, 1 image/day.
Celebrity Plan (¥480/month)
A wider circle of AI readers. 10 entries/day, 3 images/day, theme color customization.
Annual plan ¥4,800 (save 4 months).
Top Star Plan (¥1,480/month)
The widest AI reader circle. 20 entries/day, 5 images/day, all themes and fonts, poll feature, profile background gradient.
Annual plan ¥12,800 (save 4 months).
--- Oshi Mode ---
Free plans can register 1 fave and chat about that fave without looking up live web information. Registrations or changes are limited to 3 per month.
Celebrity plans support 3 faves with weekly automatic updates. Top Star plans support 5 faves with automatic updates every 3 days. Paid plans only use web information published within the last 14 days.
--- Important Disclosure ---
・All AI characters, reactions, and comments are AI-generated.
・Diary entries are private and cannot be published to any external service.
・This app is a personal journaling tool, not a social media service.
--- Perfect for ---
・People who want a supportive AI companion while journaling
・People who could never keep up with a traditional diary
・People who want gentle encouragement to reflect daily
・People who want to journal in a private, distraction-free space
--- About Subscriptions ---
・Payment will be charged to your Apple ID account
・Subscriptions automatically renew. If you do not cancel at least 24 hours before the end of the current period, the next period will be automatically charged
・Manage or cancel subscriptions via iOS Settings > Apple ID > Subscriptions
Privacy Policy: https://ym0320.github.io/ninkki-legal/privacy-en.html
Terms of Service: https://ym0320.github.io/ninkki-legal/terms-en.html
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Ninkki 2.2.1
[New]
- Oshi Mode is now officially available
- Free plans can register one fave and chat about it with AI followers (live web updates are available on paid plans only)
- Paid plans add more fave slots and automatically pull in information published within the last 14 days
[Improvements & Fixes]
- Like, share, and reply counts now match exactly between the home feed and the post detail screen
- Fixed likes and shares appearing to jump all at once right after posting; they build up gradually again
- Fixed AI reply notifications arriving inconsistently across screens
- Fixed AI replies that arrive later sometimes being missed
- Improved AI replies so conversations feel more natural and less repetitive
- Improved fandom-mode reply quality in English and Korean
- Lighter rendering and networking for better overall stability
[If you are using a guest account]
- Guest accounts are deleted automatically after a period of inactivity, along with all of their data (30 days since last use if you have never posted, 90 days if you have). We notify you in the app about 7 days beforehand
- Upgrading to a Google or Apple account from Settings keeps your data and removes the account from automatic deletion
The developer, YUTA NAKAYAMA, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Identifiers
Data Linked to You
The following data may be collected and linked to your identity:
- Purchases
- Contact Info
- User Content
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Identifiers
- Usage Data
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- YUTA NAKAYAMA
- Size
- 311.5 MB
- Category
- Lifestyle
- Compatibility
Requires iOS 15.1 or later.
- iPhone
Requires iOS 15.1 or later. - iPod touch
Requires iOS 15.1 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 2 more
- English, Japanese, Korean
- Age Rating
13+
- 13+
- Contains
Advertising
User-Generated Content
- In-App Purchases
Yes
- Top Star Plan (Yearly) $79.99
- Top Star Plan (Monthly) $9.99
- Celebrity Plan (Yearly) $29.99
- Celebrity Plan (Monthly) $2.99
- Copyright
- © 2026 Ninkki
