He drove thirty minutes at five in the morning to read a thermometer for five seconds. Then Hiroki Tomiyasu built the thing that reads it for him.
Biratori and Mukawa, Hokkaido, Japan · Hiroki Tomiyasu
Published July 21, 2026
A liberal-arts graduate who had never written a line of code taught himself to build his own farm software, and now 100 hectares in Hokkaido run on tools that started with about 7,000 yen of consumer sensors and a winter of evenings.
The story
The person and the place
Hiroki Tomiyasu came north to Hokkaido as a member of a regional revitalization cooperation squad, and started farming in 2020. He is now an executive at WFP Dacho Farm, about 100 hectares across the towns of Biratori and Mukawa, growing broccoli, soybeans, squash, and green onions.
The problem they cared about
The farm kept growing and the crew did not. 「1棟だと知れているんですが、20棟～30棟になってくると移動も含めて大変」, he told HBC. One greenhouse is manageable, but at twenty or thirty, the travel alone becomes hard. The smallest chore was the worst of them: 「朝5時。エンジンをかけて車が暖まるまで5分。ハウスまで10分。温度計を覗く。『3.2℃か…大丈夫だな』。そのまま帰る。往復30分、確認5秒。」 Five in the morning. Five minutes to warm the car, ten to the greenhouse, a glance at the thermometer, 3.2 degrees, we're fine, and drive home. Thirty minutes round trip for five seconds of looking.
The agency moment
He is a liberal-arts graduate from Kanagawa with no programming education at all. In the winter of 2025 he started teaching himself Python, then started asking AI instead of a textbook. From day nine he posted one small app a day in public, which left him nowhere to quietly quit.
He built a greenhouse temperature monitor out of consumer sensors for about 7,000 yen up front, running at zero yen a month where commercial farm IoT services charge thousands to tens of thousands monthly. He built a remote window opener from a small controller and a motor over about two months, for 60,000 to 70,000 yen in parts. 「外注すれば100万円程度はかかるかもしれません」, he told Business Insider Japan: outsourced, it might have run about a million yen. He built a GPS work logger in roughly a day. He built a bot that carries Japanese into English, Indonesian, and Khmer for the people working the fields alongside him. HBC reports that a simple program takes him about fifteen minutes to get working, at roughly a tenth of what outsourcing costs.
"チャットGPTで会話するような感覚でシステムを作っていける。トラクターの中で思いついて、トラクターの中から指示を出して、スマホがリモコンになってパソコンが勝手に作業しているみたいな" (You can build a system as though you were just having a conversation. I think of it inside the tractor, give the instruction from inside the tractor, and it is as if my phone became the remote and the computer is off doing the work on its own.) — Hiroki Tomiyasu, Sitakke (HBC Hokkaido Broadcasting)
Verified sources
Sources
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Sources last verified July 21, 2026.