PR_MAN is a Mii from the Switch.
PR_MAN never officially appeared in-game anywhere, however his Mii data file was found in Mario Golf: Super Rush. Despite being completely unused in-game, he is used in some promo art featuring Miis for the game. His Mii data file is named pr_man.mii. (Note that despite using the .mii file extension, which is a popular unofficial file extension given to Wii-format Mii data files for use in third party tools, the Mii data file is in charinfo-format.)
His Mii name in his Mii data file is PR_MAN, referring to the fact he is the male Mii golfer to be used in PR (promotional) material. His Mii ID is as follows: 8E D6 6A 58 C3 01 4F C4 AF FB 79 1B 2B CF E0 87
His Mii data file does not contain any unused Mii data.
PR_WOMAN and PR_MAN's Mii data files use the .mii file extension, which is the first time the extension has been used officially. Normally, .mii is used for unofficial third party tools dealing with Wii-format Mii data files, however, these Mii data files are using the CHARINFO format. Miitopia (Switch) also uses the CHARINFO format, and simply gives its Miis the .charinfo file extension.