Or, you know.
Literally: heaven – clothing – no – stitch
Alternately: Naturally flawless and beautiful. Amazingly well-made, without any sign of artifice. Usually refers to poetry, or to a person’s unaffected innocence of character.
Notes: A number of East Asian folktales include Tennin or Tennyo (天人, 天女), “heavenly people,” whose beautiful clothing has no visible stitching.
Apparently this yojijukugo goes back to the Song Dynasty in China, from a collection of stories known as the Taiping Guangji (太平広記), Taihei kouki in Japanese.