TNK Co., Ltd. (Japanese: 株式会社ティー・エヌ・ケー, Hepburn: Kabushiki-gaisha Tii Enu Kee) is a Japanese animation studio located in Nerima, Tokyo Prefecture. It was established on January 29, 1999 by Nagateru Kato, a former animator from Tatsunoko Production. They have produced a number of series to date, most notably their adaptations of School Days and High School DxD, among others such as Hand Maid May, I My Me! Strawberry Eggs, UFO Ultramaiden Valkyrie, and Kannazuki no Miko.