It originally aired from June 3 to July 7, 2018 in the United States on Adult Swim's Toonami programming block.

In Japan, Progressive received a theatrical screening as a compilation film, with it opening on September 28, 2018.

[3] In addition to providing several tracks for the season, the Pillows performed the ending theme song "Spiky Seeds".

In this season, Haruko returns to Earth years later after a failed attempt to contain Atomsk, although she did manage to absorb him.

Placing herself as a middle school homeroom teacher, Haruko targets a 14-year-old girl named Hidomi Hibajiri through her classmate and eventual love interest Ko Ide.