Are there opportunities to learn Japanese after joining the company?

Yes, while it varies depending on your status of residence and the accepting company (workplace), there are opportunities to learn Japanese while working.

【Specified Skilled Worker】
Many workplaces allow you to learn Japanese by using it on the job, and senior employees often teach you patiently using simple Japanese.
In addition, accepting companies or Registered Support Organizations may provide learning support, allowing you to improve gradually even if you start at the N4 level.

[Technical Intern Training Program / Employment for Skill Development]
Japanese language learning is included in the program, and the premise is that you will work while studying Japanese after joining the company.
The idea is to gradually improve your skills with the goal of reaching the N4 level, and there are systems in place to consult with support organizations and companies.

[Engineer/Specialist in Humanities/International Services]
This varies by company, but since a certain level of Japanese proficiency is required for the job, self-directed study is often the main focus after joining the company.
Some companies may offer business Japanese training programs.