harukary
Japanese English
harukary icon

harukary

Software designed to remain useful in everyday life and work.

We plan, develop, and operate mobile apps, web services, and AI-powered software.

X note Izanami

Products

Simple apps and web services designed for long-term use in everyday life.

100 Year Diary Local

Live

A local-first diary app for revisiting the same date year by year.

  • Revisit the same date across years
  • No account required, entries stay on device
  • Export your diary as a Zip file
Cover image of 100 Year Diary Local

tomomemo

Live

A local-first app to keep your friends' profiles and interaction history like a profile notebook.

  • No login required, fully local storage
  • Profile notebook that still works with partial information
  • Lightweight interaction logs organized by date
Cover image of tomomemo

piko

Live

An app for recording plants and animals you notice on walks, then revisiting them as your own field guide.

  • Save plants and animals the moment you notice them
  • Revisit your observations through list, calendar, and map views
  • Turn everyday walks into a field guide that grows over time
Cover image of piko
View all products（9）

Developer tools

Tools I built for my own development, shared as-is.

Take a look →

Writing

Posts and notes on what I learn while building. (Japanese)

  • Note
    ChatGPTとCodexのコンテキストはどう違うか

    ChatGPTで観測できた履歴の残り方と、Codexの公開実装を、保存・コンテキスト構築・モデル入力の3層に分けて整理する。

  • Note
    ChatGPTから複数のCodex運用を調整する

    Codex App ServerをCronで継続実行し、ChatGPTからローカルPC接続MCP経由で複数Cronの運用方針を調整する構成と、その利点を整理する。

  • Note
    GPT-5.6とClaudeのコスト比較

    GPT-5.6 Sol/Terra/LunaとClaude Fable/Opus/Sonnet/Haikuを、エージェント用途のInput/Outputコストで整理する暫定メモ。

  • Note
    Command Code が安い理由

    Command Code の低価格プランが成立する理由について、確認できた料金構造と推定を整理したメモ。

  • Note
    Oracle

    steipete/oracle は、AIエージェントやCLIから別の強いモデルに相談するためのCLI/MCPツール。

View blog posts View notes

Contact

Work inquiries, app feedback, and bug reports are all welcome.

You can reveal, copy, or open the email app.