Peernovo
Specialist professionals not classified elsewhere

How to become a Private Investigator

Also called: Inquiry agent

Carries out field investigations for clients, such as making enquiries in person, following people and keeping watch, to gather information on where someone is or what they are doing, and reports the results to the client.

How to become one

No particular qualifications are needed to start, as long as you have around a high school education. More people are hired mid-career than as new graduates. Personal connections and job sites are both used. Training after joining varies between agencies, but under the Detective Business Act, agencies must give their staff the education needed to carry out investigations properly. Some run in-house training on laws such as the Detective Business Act, the Penal Code and the Act on the Protection of Personal Information and on proper investigation methods, or send staff to study sessions run by industry bodies. How to carry out field investigations is learned mainly on the job. After gaining experience as an investigator, some people open their own agency or move to another agency. You may drive cars or motorbikes during field investigations, so a standard driving licence or motorcycle licence is useful. Up-to-date knowledge of electronic equipment such as video cameras, and the ability to use it properly, helps in gathering information in the field. You also need legal knowledge to judge whether your methods are lawful. Writing skills and general computer skills are needed to write reports. You also need to be discreet, because keeping secrets learned in the job is important; patience and stamina for long periods of following and watching; concentration and quick reactions so you do not miss chances to gather information; and the ability to stay calm when sudden or unexpected things happen.

Ways in

Pay · Job openings · AI and this job

Related jobs

Not sure this is for you? Take the 2-minute career quiz

Questions people ask

How do I become a Private Investigator?

No particular qualifications are needed to start, as long as you have around a high school education. More people are hired mid-career than as new graduates. Personal connections and job sites are both used. Training after joining varies between agencies, but under the Detective Business Act, agencies must give their staff the education needed to carry out investigations properly. Some run in-house training on laws such as the Detective Business Act, the Penal Code and the Act on the Protection of Personal Information and on proper investigation methods, or send staff to study sessions run by industry bodies. How to carry out field investigations is learned mainly on the job. After gaining experience as an investigator, some people open their own agency or move to another agency. You may drive cars or motorbikes during field investigations, so a standard driving licence or motorcycle licence is useful. Up-to-date knowledge of electronic equipment such as video cameras, and the ability to use it properly, helps in gathering information in the field. You also need legal knowledge to judge whether your methods are lawful. Writing skills and general computer skills are needed to write reports. You also need to be discreet, because keeping secrets learned in the job is important; patience and stamina for long periods of following and watching; concentration and quick reactions so you do not miss chances to gather information; and the ability to stay calm when sudden or unexpected things happen.

How much does a Private Investigator earn in Japan?

Average annual income in the private sector, bonus included, is ¥5,833,100 (Ministry of Health, Labour and Welfare). The figure is for the wage survey group Specialist professionals not classified elsewhere, which covers several jobs.

Do you need a degree to become a Private Investigator?

Usually. In this job's census occupation group, 67% of workers are university graduates.

Will AI change the work of a Private Investigator?

Generative AI can do relatively little of this work, by the ILO's global estimate.

Sources

独立行政法人労働政策研究・研修機構（JILPT）作成 職業情報データベース 解説系ダウンロードデータ（IPD_DL_description_7_01.xlsx）ver.7.01 職業情報提供サイト（job tag）より2026年10月4日にダウンロード（https://shigoto.mhlw.go.jp/User/download）を加工して作成

独立行政法人労働政策研究・研修機構（JILPT）作成 職業情報データベース 簡易版数値系ダウンロードデータ（IPD_DL_numeric_7_00.xlsx）ver.7.00 職業情報提供サイト（job tag）より2026年10月4日にダウンロード（https://shigoto.mhlw.go.jp/User/download）を加工して作成

Sources: JILPT Occupational Information Database download data via job tag (解説系 ver.7.01 and 簡易版数値系 ver.7.00, downloaded 4 October 2026), processed by Peernovo; MHLW, Basic Survey on Wage Structure 2025; Statistics Bureau of Japan, 2020 Population Census; MEXT, School Basic Survey 2025; MHLW, Employment Referrals for General Workers (Hello Work statistics). Figures processed by Peernovo. English job names, translations and the matching of jobs to statistical groups, schools and degree fields by Peernovo.

Updated 4 October 2026