Building a company
with AI, while
keeping judgment human浩
I'm Hiro Kuwana (桑名浩行). I build Kaiwa full-time and write down the product calls, systems, mistakes, and small wins along the way.
Projects Things I tend, and things I have set down.
fig. 1 · kaiwaKaiwa augment language coaches
A platform where language learners speak daily with AI, and coaches can architect and individualize learner journeys
28k organic visitors / mo · 2,000+ learners
open →
fig. 2 · exonians in japanExonians in Japan a fast community platform
A small, practical alumni site I built on a subway ride home. Focused on photos and community building
open → fig. 3 · kaiwa reddit scoutKaiwa Reddit Scout signal-finding for language learners
A local workflow that connects Reddit, Drive, and Gemini to find language learners with real intent.
open →
fig. 4 · flybyrdFlybyrd AI for product managers
Organizing scattered feedback for product managers. A practical, private dashboard for the signals that matter.
open → fig. 5 · pebblrPebblr connecting nonprofits and donors/volunteers
A nonprofit donor experiment that taught me where human trust matters more than platform mechanics.
open →Notes from the build, and the questions underneath it.
./ai-guides
道 具A self-editing system prompt for technical writing
Turns drafts into clean docs without flattening the author's voice. Iterates on itself in two passes.
How I run a 4-model debate to find a position I trust
A small harness that lets disagreement keep going until the useful shape appears.
Local-first prompt versioning with plain text + git
No fancy IDE. Just folders, frontmatter, and diffs that read like edits.
essays
作 文Your Funnel Is a Lie
Why Markov chains are a better mental model for SaaS growth than the traditional sales funnel.
On Building for Decades
Why simplicity wins in the long run when building personal infrastructure.
What I mean when I say augment
A working definition with edges. The word does a lot of heavy lifting in my work.