Looking at 2018 figures for number of temporary agency workers by job type as well as the corresponding ratios, the combined male and female total is highest for Clerical work at 440,000 (32.4%), followed by Manufacturing at 350,000 (25.7%), and Transportation/Cleaning/Packaging at 200,000 (14.7%).
These results show the needs of client companies to secure human resources that can be effective immediately after hire and to take on specialist work, as well as to adjust employment numbers depending on demand.

[Reference] "Labor Force Survey" by the Ministry of Internal Affairs and Communications (2018)

Marked differences can be seen when comparing the job types of male and female workers. Manufacturing-related jobs were most common for males at 190,000 (37.3%), followed by Transportation/Cleaning/Packaging at 110,000 (21.6%), and Specialist/Engineer at 60,000 (11.8%). Female workers were most likely to do Clerical work, which accounted for 390,000 female workers (45.9%), followed by Manufacturing at 160,000 (18.8%), and Transportation/Cleaning/Packaging at 90,000 (10.6%).

[Reference] "Labor Force Survey" by the Ministry of Internal Affairs and Communications (2018)