In Ryuu ga Gotoku 8 (aka Like a Dragon Infinite Wealth), when asked about getting with a younger lady, a character says the line "[彼女{かのじょ}]下手{へた}すりゃふた回{まわ}りも年下{としした}だぞ" ("at worst, [she] could be like two dozen years younger than me").
I've never heard this 回り counter for 12-year periods, and I was just wondering:
- is it a commonly known/used counter? If it matters, the character who said the line was born in the early 80s.
- is there any reason why 12-years in particular would get its own counter? And perhaps on a related note, is there any reason the counter is 回り (turning, revolving, orbiting, etc.)?