Pricing for PI services in Japan varies enormously. The same investigation can cost twice as much in central Tokyo as in a smaller city, and a multi-day package costs far more than a single-day spot check.
The key is to get a written, itemized quote — not just a headline figure.
Why prices vary so much
Factors that drive cost up or down include:
- Type of investigation (infidelity, missing person, background check, etc.)
- Number of investigators required
- Hours or days of surveillance
- Area (urban areas cost more)
- Subject's behavior patterns (unpredictable subjects need more time)
- Night or early-morning work
- Vehicle and equipment needed
- Report complexity
Common pricing models
Hourly rate — you pay per investigator-hour. Transparent but costs can escalate if the subject is active longer than expected.
Package (パック制) — a fixed number of hours or days at a set price. Easier to budget; the most common model for infidelity cases.
Success fee (成功報酬) — a retainer plus a bonus if a defined result is achieved. The definition of "success" must be in writing before you agree.
Fixed fee — common for standardized services like a bug sweep or a single location check.
What the headline price often excludes
Always ask if these are included:
- Vehicle and fuel fees
- Public transport fares
- Written report preparation
- Overtime when surveillance runs long
- Out-of-area travel
- Equipment rental
Quote checklist
Before you sign, get written answers to:
- How many investigators are included?
- What is the minimum contract period?
- Are vehicle, transport, and report fees included?
- What is the overtime rate and when does it apply?
- How is "success" defined (for success-fee plans)?
- What is the cancellation policy and when does a cancellation fee apply?
- How will my data and report be stored and deleted?
Do not choose on price alone
A very low headline price is often offset by high extras. Prioritize agencies that give you a clear, all-inclusive quote over those who lead with a low number and add on costs later.
For agency selection tips see How to choose an agency.
FAQ
What is a typical price range for an infidelity investigation?
Costs vary too much to quote a reliable number without knowing the area, duration, and scope. A one-day package in a major city typically starts in the low-to-mid six figures (JPY). Multi-day packages cost substantially more. Get an itemized quote before committing.
Is the initial consultation free?
Many agencies offer a free initial consultation, but confirm this before you call — some charge a consultation fee.
Are there hidden fees I should watch for?
The most common extras are vehicle fees, transport, late-night surcharges, and the written report. Ask for a fully itemized quote that lists every possible charge before you agree.
Can I pay in installments?
It depends on the agency. A retainer is usually required upfront; some agencies accept installments for the balance. Confirm before signing.