ARC RUNTIMEアーク・ランタイム
日本語
Independent projects · Tokyo / SF

Tools and games for curious minds.

Collect Japanese words. Find a note by ear. Make music by moving things around. Useful things with a playful streak.

Explore the work

ARC RUNTIME

01 · Work

A closer look at the projects.

Different ways to learn and make.

Narelog example word card for 乗り換え, with reading, meaning and a saved-to-set state.
Illustration from the current public site

Narelog

ナレログ
Private beta

Look up Japanese words, save them to sets, and return to them in practice. Keep the words you find in one place.

The app requires beta access. The public site explains the features and their limits.

Case notes
Problem
When lookup and practice happen in separate places, reviewing a Japanese word can mean copying it into another tool first.
What I built
One place to look up a Japanese word, save it to a set, and come back to it in practice. A saved word is ready for review without entering it again.
Approach and tradeoff
Saving is a separate step from lookup. You choose which words to add to review. The tradeoff is one more step for each word you want to keep.
Current limits
The current beta is a limited release focused on study. Using the app requires beta access, so the link here goes to the public site.
Explore Narelog
Lodestone’s Home and Away lesson above its pale teal and purple piano keys.
Browser ear-training app

Lodestone

ロードストーン
Browser beta

Hear a note and learn its place in a key. Start with two contrasting sounds, then try finding them by ear.

Opens the browser beta. On iPhone, use Safari; Home Screen audio is unresolved.

Case notes
Problem
Hearing where a note sits in a key is a skill you build by ear, with practice.
What I built
A browser ear-training app with on-screen piano keys and a guided first lesson. Practice starts with two contrasting sounds.
Approach and tradeoff
The lesson plays each sound before revealing its key, then lets you explore the introduced keys. Starting with two sounds keeps the first exercise focused, but covers only a small part of the key.
Current limits
The browser beta is in English only. On iPhone, use Safari; audio has an unresolved problem when the app is opened from the Home Screen.
Try Lodestone
Plink’s Paper island, with a pot, pan, bowl and leaf placed across pitch and rhythm lanes.
Arrange objects to shape the music
プリンク
Public experimental demo

Place objects in the rain and turn their positions into music. Jam adds a rule-based layer of chords, bass, and rhythm.

Opens the demo in English. Choose Start sound when you are ready to listen.

Case notes
Problem
Can arranging objects in a scene work as a way to make music? Plink is a prototype for testing that.
What I built
A scene where you place objects in the rain. Where each object sits across the pitch and rhythm lanes shapes the music it makes.
Approach and tradeoff
Object positions supply pitch and rhythm inputs. Jam uses local rules to add chords, bass, and rhythm without a cloud AI service. Music generation stays in the browser; it does not learn from audio recordings.
Current limits
A public experimental demo of a procedural music prototype. There is no save or export yet. Behavior on a real iPhone and the musical results still need evaluation.
Try Plink

02 · Workshop

On the bench.

Early experiments, each with a specific question to work through. No public demos yet.

  • Cratewise

    Prototype

    A music-library organizer that checks exported track metadata and helps build collections.

  • Genre listening

    In development

    An experiment in hearing the differences between deep house and melodic house. Teaching examples and audio are still being evaluated.

  • Threshold

    Prototype direction

    A combat experiment built around stopping time, planning actions, and the delay before acting again.

03 · About

Practical on the surface. A little mystery underneath.

Arc Runtime is where I make my own things. I grew up in the Bay Area, have lived in Japan for over a decade, and come from product marketing.

I want each project to make sense in the first ten seconds and still give you something to discover after a hundred tries. Something useful, with a little room to play.

  1. Start with an action

    Give people something concrete to try, then make the next step clear.

  2. Leave room to explore

    A useful tool can also invite a little experimentation.

  3. Make sense in both languages

    English and Japanese should carry the same idea, in words that fit each language.

04 · Beta testing

Coming soon.