The Third Heart is a psychological music video, released as a single episode, set to the song Daisan no Shinzou. Harumaki Gohan directed and animated it and also wrote the music, while Hatsune Miku sings. Two versions of the song exist: the Vocaloid original with Miku went up on May 15, 2021, and Harumaki Gohan's own cover arrived later, on May 23, 2021.