The Teke Teke (or Tek Tek) is a Japanese urban legend about a girl who fell on a railway line and was cut in two. Now as a ghost, she carries a scythe and travels on her hands searching for victims to cut in two, mimicking her accident.
The legend is called "Teke Teke" because of the sound she makes while "walking" and carrying the scythe.
The rumor to make Tek Tek appear in Kasugayama High School can be obtained from the Pathetic Loser on the Hirasaka Ward Map. Defeating Tek Tek earns Tek Tek's Name Tag, which can then be traded for a Soma.