TSTS was founded by designer Takuya Sasaki and pattern maker Yurie Isashi. Sasaki (b. 1990, Aomori) graduated from Bunka Fashion College and studied at the Royal Academy of Fine Arts Antwerp, apprenticing under Walter Van Beirendonck. Isashi (b. 1990, Tokyo) graduated from Bunka Fashion College and worked as a corporate pattern maker before moving to Antwerp to assist Sasaki in the production of his collection, while concurrently working as a professor and modelist at the Royal Academy of Fine Arts. After returning to Japan in 2016, the duo worked separately at various collection brands, before launching TSTS together from the A/W 2023-24 season.