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The right words start with understanding.

Ask about the meaning behind a phrase. Find natural words for the moment. Keep what you want to use again.

Explore Koto
The native Koto iPhone app, showing a message to a friendKoto Web Memory workspace in an official MacBook Pro frame
Koto for iPhone and Koto Web · Illustrative account content.

Understand

Meaning lives in the moment.

「また今度」 can leave a plan open. Koto helps you explore what a phrase might mean—and what is still uncertain.

“Another time”また今度

The same words can land differently depending on the moment.

The relationship

Between close friends, it could be a warm invitation to reconnect.

The tone

A gentle reply can leave the timing open without closing the door.

What remains uncertain

Without a date or follow-up, it is not a confirmed plan.

A possible reading, not a verdict on someone’s intentions.

Keep what matters

From one conversation to words you can return to.

A useful expression stays with its meaning and the situation that made it matter.

Swipe, choose a moment, or play the story.

Koto Ask screen with a conversation prompt
Illustrative demo · Not a live AI response.

Illustrative demo · Not a live AI response.

Koto Ask screen with a conversation prompt

Start with a real question.

Tell Koto what happened, who you are speaking to, and how you want your words to feel. A useful answer starts with the situation—not a word-for-word swap.

Here, the question is how to write warmly to a close friend in Japanese.

Koto explaining the possible meaning of また今度
Illustrative demo · Not a live AI response.

Illustrative demo · Not a live AI response.

Koto explaining the possible meaning of また今度

Look beyond a translation.

Ask what a phrase might mean in this relationship. Koto can unpack the nuance while making room for what the words alone cannot tell you.

「また今度」 leaves the timing open; context matters more than a literal gloss.

A Japanese expression saved in Koto with its meaning and context
Illustrative demo · Not a live AI response.

Illustrative demo · Not a live AI response.

A Japanese expression saved in Koto with its meaning and context

Keep the reason, not just the phrase.

When an expression is worth keeping, save it with its meaning and the situation that made it useful. The context is there when you return.

A warm follow-up to a close friend becomes more than an isolated sentence.

Koto Revisit card with a saved Japanese expression revealed
Illustrative demo · Not a live AI response.

Illustrative demo · Not a live AI response.

Koto Revisit card with a saved Japanese expression revealed

Bring it back in your own time.

Come back to a saved expression and try to remember it before revealing the answer. Review stays connected to language you actually wanted to use.

No streak to protect—just the phrase, its meaning, and your own pace.

Ask

More ways to use Koto

A closer look at Koto.

Get help with a message and leave, or keep what you learned for later. These are choices, not steps you have to complete.

Appearance

Make Koto feel like yours.

Koto Style brings the app’s colors, controls, and wallpaper together. Choose from five real styles, from the warm Koto Classic to the dark Midnight Ink. Light, Dark, and System appearance are separate choices; you can also use Your Photo as a personal wallpaper.

Koto Classic Koto Style preview from the app
Koto Classic

Warm paper, indigo, and coral.

These are crops of the current Koto Style picker. This website preview does not change your app.

Personalization

Shaped by what you choose.

Set your language direction, level, learning focus, and reading aids. When you ask a question, tell Koto who you are speaking to and what you want to say. Those details help the answer fit the moment, without pretending to know someone else’s mind.

Koto is not individually training an AI model on you. Temporary conversations do not send the ordinary learner context used for supported learning requests.

Choose your starting point

Your selected direction and reading support shape how Koto presents language.

Describe this moment

The situation and tone you provide belong to this question. You can simply get help and move on.

Keep only what matters

A deliberate save keeps a useful expression with its context for Memory and possible review. It does not save every conversation.

Koto suggesting wording for a warm message to a friend

Talk with Koto · Beta

Practice before the conversation happens.

Choose a situation and a goal, then practice a conversation at your own pace. Guided practice gives you time to prepare each reply.

How it works

  1. Choose a moment

    Start with a situation, like making plans with a friend, and set a goal.

  2. Take a turn

    Read or hear Koto’s prompt. Speak or type your reply, with Help when you need it.

  3. Look back

    Finish for a short recap. Where offered, keep a useful expression for later.

Beta: replies and feedback may be inaccurate. Natural conversation is marked “In development”; this is guided turn-taking, not interruption-capable live voice chat.

Talk with Koto guided practice: Koto asks about Sunday while a learner prepares a Japanese reply before sending
A full Guided practice screen: Koto asks about Sunday while you prepare a reply. Captured in an offline local preview.

Memory & Revisit

Keep the language you want to use again.

Save an expression because it answered a real question. Koto can keep its meaning, reading, situation, and notes together. Eligible saved expressions can then appear in Revisit: recall the meaning first, reveal the expression, and choose “Still learning” or “Got it” to guide when it returns.

A word you saved from a real question becomes a card you can recall, not just an answer you once saw.

Ordinary saved learning expressions can enter review; sensitive or paused items do not. Optional local reminders require notification permission.

Reveal a flashcard, then swipe left or right to review it.

Useful when the moment calls for it

Both directions

Ask in English for natural Japanese, or begin in Japanese and work toward natural English.

Listen and slow down

Hear an expression at a natural or slower pace where playback is available.

Bring the words with you

Ask about a photo, camera image, or supported image file; choose reading aids when Japanese text needs more support.

Koto for iPad

Made for the bigger picture.

On iPad, a few tools use the extra space in ways they cannot on iPhone. See the current iPad build in action.

View the iPad in

Swipe, choose a view, or play the story.

Current full-screen Koto iPad build showing a saved expression and its context over Ask

Scroll sideways to inspect the iPad screen.

Current full-screen Koto iPad build showing a saved expression and its context over Ask

Memory beside Ask

Bring a saved expression back into view.

Open a saved expression from a conversation. Its meaning and original situation stay in view while you decide what to quote in a new question.

An iPad-only saved-expression inspector.

Current full-screen Koto iPad build showing Read with Koto and a selected passage over Ask

Scroll sideways to inspect the iPad screen.

Current full-screen Koto iPad build showing Read with Koto and a selected passage over Ask

Read beside Ask

Keep the text beside the conversation.

Read with Koto opens a passage from Ask. Select a line from the source and bring it into your question without losing your place.

An iPad-only reading pane, shown with local sample text.

Current Koto iPad build with the native conversation sidebar open beside Ask

Scroll sideways to inspect the iPad screen.

Current Koto iPad build with the native conversation sidebar open beside Ask

Native sidebar

Keep the conversation in view.

The iPad layout gives conversations a native sidebar. Return to an earlier exchange or begin a new question without replacing the main workspace.

An iPad-specific navigation layout.

Memory beside Ask

Made for the in-between moments.

Context before certainty

A phrase can mean more than one thing. Explore the situation without assuming you know someone’s mind.

The thinking behind Koto, its name, and Kiko.

Read Our Story

Koto Web is now available for private testing.

Ask, save, and revisit useful English and Japanese in your browser. Sign in and enter your invitation code to get started.

Go to Koto Web App Invitation required.
Koto Web learning Home in an official iMac frameKoto Web Memory workspace in an official MacBook Pro frame
A personal English–Japanese workspace in your browser. Displayed account content is illustrative.
Koto app icon

Current availability

Koto for iPhone is coming soon.

Koto for iPhone is available to invited testers through a private TestFlight beta. The app is still being tested and refined.

Read beta support
TestFlight · Invitation only