In Episode 54 of Yugi-Oh, Seto Kaiba is so in awe with the Ultimage Dragon’s beauty that he mispronounces “utsukushii” (美しい, means “beautiful”) as “futsukushii”. After Kaiba became popular in Nico Nico Douga, the users started using the word to describe something so beautiful that they're moved by the mere sight of it.
