TIL a Japanese euphemism for getting your period is 'ペリー来航 - the arrival of Matthew Perry'

https://www.thinx.com/thinx/blogs/periodical/odds-and-ends/period-euphemisms-from-around-the-world

https://www.reddit.com/r/todayilearned/comments/15x6kcg/til_a_japanese_euphemism_for_getting_your_period/