Paato, short for paato taima, is the everyday word for part-timers. The legal definition, in the Part-time and Fixed-term Employment Act, is a worker whose scheduled weekly hours are shorter than those of a regular full-time worker at the same employer. In common use, paato suggests an adult, often a married woman, working fixed shifts in retail, food, care or offices, while arubaito suggests a student or a younger worker. The law draws no line between the two.
The Labour Force Survey counted about 10.3 million paato in 2025, nearly half of the 21.3 million non-regular employees. Many are on fixed-term contracts, which brings the five-year conversion rule into play. Since April 2020, and April 2021 for smaller employers, the equal-pay rules prohibit unreasonable differences in pay and benefits with regular staff doing comparable work.
Hours have been shaped by the income walls. Part-timers join employee pension and health insurance if they work 20 hours or more a week at an employer with 51 or more staff, are not students and expect to stay more than two months. The 88,000-yen monthly wage test was abolished on 1 October 2026, and the employer-size test falls to 36 or more employees in October 2027, 21 in October 2029 and 11 in October 2032 before ending in October 2035, so more part-timers will be covered.
What it means for a foreign employer
- Part-time does not mean fewer rights. Paid leave accrues pro rata, dismissal rules apply in full, and pay differences with full-timers need a reason you can explain.
- Expect hours to be managed around thresholds. Some part-timers ask to stay under the insurance or tax lines. As the thresholds change, both cost and preferences will shift.
- It is a talent pool for some roles. Experienced professionals, often women returning after childcare, take part-time roles they are overqualified for because few employers offer senior part-time work. A well-designed part-time professional role can attract strong candidates.
Sources
- Part-time and Fixed-term Employment Act, Articles 2 and 8.
- Ministry of Internal Affairs and Communications, Labour Force Survey (Detailed Tabulation), 2025 annual average.
- Employees' Pension Insurance Act, as amended by the 2025 pension reform law (enacted June 2025).