I’m a little sad that my Japanese isn’t good enough to tell you the complete story behind this assuming there is one. From what I can gather the original Japanese post is just a blog post about geeky T-Shirts, and it happens to have this Kimono in it too.
The homemade (I assume?) Mario Kimono has a scent from Super Mario Bros embroidered on the “Obi” and the start screen on the back, as well as having Mario, Peach, Bowser a Boo and a 1-Up mushroom on the kimono.
The Famicom (What the Japanese NES was) controller obi tie makes it perfect.
Incidentally the same post also has this pretty cool Gameboy Dress:
And these funky Gamer tights:
This is the 21st in a series of “Show Me Your Gamer Shirts” Blog posts by this blogger, so there is a lot more to see there.