SDoS LLC — Saitama, Japan
An AI company that knows the job site.
Our founder ran a construction company and designed plumbing systems. Now he builds AI for builders and MEP contractors, with his own hands. The first answer is GAISAN (概算, “rough estimate”): drop in the drawings and get an itemized estimate plus a list of the questions a human still has to answer.
Like a sangaku: problem, method, answer.
In Edo-period Japan, mathematicians painted a problem, its method and its answer on a wooden tablet (算額, sangaku) and hung it in a shrine for anyone to check. SDoS works the same way. The problem is the drawing, the method is AI, the answer is the estimate. The only thing we keep hidden is which AI models we use.
Plans, specs, site photos. LINE works too.
Takes off quantities and maps them to the items and unit rates from your own past estimates.
A rough estimate, plus a question sheet for everything that needs a human.
What comes out
A sample, not real prices. When the AI cannot decide a line, it does not guess: the line is marked “to confirm” and becomes a question. Only unmarked lines were actually read from the documents.
| Item | Spec | Qty | Unit | Rate (JPY) | Amount (JPY) | Status |
|---|---|---|---|---|---|---|
| Water supply pipe | HIVP 20A | 38.0 | m | 2,400 | 91,200 | 済 read from drawing |
| Drain pipe | VP 75A | 21.5 | m | 3,100 | 66,650 | 済 read from drawing |
| Vanity unit | W750 | 1 | ea | — | — | To confirm (model no.) |
| Delivery route | — | — | — | — | — | To confirm (no drawing) |
House rules
Your drawings never train a model
Drawings and estimates are stored only as that company’s private reference. They are never used to train AI models, shown to other companies, or pooled into cross-company price data. Deletion on request.
Say “we don’t know” when we don’t
Undecidable lines are not filled by guesswork. Every number comes with its basis. GAISAN is not a final quote; it shortens the work before one.
Operated in Japan
All analysis is run and operated by SDoS in Japan. Part of the processing uses an AI provider in the United States under contract terms that exclude training and delete data within 30 days.
Built with a site worker’s eye
Every screen is laid out like a drawing sheet: grid paper, ink lines, a title block in the corner. The standard is that a builder can read it the way they read a plan.
Founder
Kohei Honda
Representative Member
Studied architectural and building-services design at Aoyama Technical College, worked on interior and construction sites, ran a construction company, and founded SDoS LLC on 3 March 2026. He builds GAISAN himself because he wanted to stop spending nights and weekends preparing estimates.
The name comes from “Six Degrees of Separation”: six introductions connect you to anyone on earth. A name for a small company that intends to reach the world.
Drawing no. SD-369 and scale 1:369 are those three numbers.