I haven't found a osomiitsu blog, but I think there is a miitomatsu one (it's centered around that one Nintendo app called miitomo). However, it's kind of inactive
OSOMIITSU-SAN REIGNS SUPREME THEN!!
But no, seriously. Me and @lokedoodles were just fooling around since my computer autocorrects “Nii-san” to “Mii-san” and came up with this:
“Ferris ☆*・゜゚・*\(^O^)/*・゜゚・*☆: funtimes with mii-sanLoke: haha I feelLoke: lol I justLoke: keep imagining karamatsu as a miiLoke: helpFerris ☆*・゜゚・*\(^O^)/*・゜゚・*☆: ….stupid mii-sanFerris ☆*・゜゚・*\(^O^)/*・゜゚・*☆: dude imagine him dancing to the wii shop musicFerris ☆*・゜゚・*\(^O^)/*・゜゚・*☆: as a miiLoke: like, the others are normal, it's just karamatsuhe's justA miiFerris ☆*・゜゚・*\(^O^)/*・゜゚・*☆: not even a good miiLoke: a really dumb looking mii”
So then we came up with: “An Osomatsu-san AU where everything is the same except Karamatsu is a terribly made Mii.” And I went online looking for an emulator and found it.
The rest is history and Osomiitsu-san was born.
I didn’t even know there was another blog with a similar premise. It’s kind of glorious actually.