[quote=@Keyguyperson] Oh, wasn't that part of that big romanized spelling change that they did? I remember hearing some random tidbit of info on it a while back. [/quote] EDIT: Apparently I'm like super-wrong about the senpai/sempai thing. At least pronounciation-wise (see Anime_Freak's post.) The romanisation is still "senpai". ORIGINAL: Back in '54? Yeah, it was when the Japanese government were trying to figure out which romanisation system to adopt. In '30 they put up a committee to figure it out and finally decided on Nihon-shiki (now known as Kunrei-shiki) in '37. But the US being the US, in '45, after WWII, the occupying Allies came in and declared Hepburn to be the official system, because apparently Nihon-shiki had "militaristic associations" or some bollocks. It wasn't until '54 that the Japanese government officially confirmed a slightly-modified Nihon-shiki as the official one again. Hepburn 3rd edition - also known as modern Hepburn, the one that made this change - was released the same year. Funnily enough Hepburn is actually the most used system today. I use/used it in class while learning hiragana. Anyway, that's the only occasion I can find reference to in which there was enough simultaneous change to maybe be considered "major". Idk maybe I'm looking in the wrong places.