I'm Kenji Sakuramoto. I run ｋｅｎｓａｕｒｕｓ LLC, a studio in Shibuya, Tokyo, founded in June 2025, and I run more than ten repos on my own. Most of what I've shipped started with a problem in my own life.

The problems first

  • lets-talk. I was socially awkward when I was young, and it took me years to read between the lines. Meeting people from other countries, who talk and show what they feel in very different ways, changed things for me. I'm still learning. lets-talk is a place to practise the hard reply before you send it.
  • help her take photo. On trips I'm usually the one taking the photos, and my wife usually tells me off on the spot. Retake, retake. The app puts the camera's live view on the other phone, so the person in the photo can direct the shot and press the shutter.
  • glot.it. I speak several languages, and a new one sticks faster when I tie it to one I already know. glot.it teaches Thai and writes its memory hints in the learner's own language.
  • yen-yen. With the money app I used before, sharing one book with my family in real time was hard. yen-yen is a hand-entered household money book that a couple or a family can share, with no bank link.
  • the wanting mind. A free book that follows one question: why do people want? It started when I lived in meritocratic Singapore and then came back to Japan.
  • kenji skills. The one I built for myself as a developer, covered below.

The rule that makes one person enough

Agents stop halfway. Sometimes they report "done" when it isn't. With one person and more than ten repos, I needed the same steps and the same definition of done everywhere, so I wrote them down as playbooks.

The part that matters most: the agent that did the work doesn't get to say it's finished. A separate reviewer, instructed to work read-only, compares the plan, the diff and freshly re-run checks, and answers PASS, CONTINUE or BLOCKED. If the evidence is missing, the answer is CONTINUE.

Bug reports work the same way. Reports from my bug-reporting tool, Mushi Mushi, feed fix runs that end in a pull request, and I merge each one by hand.

Why I keep going

With AI, one person can now build a lot. If more people build for themselves and for the people around them, clearing small everyday chores one at a time, life gets a little easier for everyone. I'd like to be one of them.

The longer version is on the maker page.

An AI assistant drafted this post from my own answers, and it was fact-checked before publishing. The facts about each app come from its repository and its live listing.