EXCLUSIVE AT MRPORTER.COM. The foundation of every well-dressed man’s wardrobe is his undergarments – with that in mind, we wanted to make our Mr P. selection as sharp as they are comfortable. These black socks have been made in Japan from a breathable cotton-blend and ribbed for a snug fit. Pick them up in merlot too if you’re replenishing your underwear drawer. Explore the world of Mr P. – – Black cotton-blend – 90% cotton, 10% nylon – Made in Japan- For Men.