Part-time Work and Dependent Visa Rules in Japan – Need Clarification

Hi all,

My wife, who is on a dependent visa, recently started working part-time. She's currently covered under my pension and health insurance. I understand that as long as her annual income stays below 1.3 million yen, she won't need to register for her own pension and health insurance. Additionally, I know there’s a rule where her income shouldn't exceed 108,000 yen for three consecutive months.

My question is: if she earns, say, 200,000 yen for two consecutive months and then 100,000 yen the following month, would that violate the 108,000 yen rule? I'm making sure her total income remains below 1.3 million yen yearly, but I want to ensure we're not crossing any monthly thresholds.

Also, she receives a commuting allowance for the subway. I’m assuming this amount is included in her income for these calculations, but can anyone confirm if that’s correct?

Thanks in advance for your insights!