Known for voicing Space Dandy in Space Dandy and Romano in Hetalia, Ian Sinclair has been confirmed to play Sousuke Yamazaki. With this announcement, Funimation also revealed the voice actress playing the representation of the entire Free! fandom, Gou Matsuoka, as Jamie Maachi, known for her roles as Panty in Panty & Stocking, Rias Gremory in Higschool DxD and the narrator of Hetalia.
Ending the week with a bang, the voice actors for the supporting cast has also been made public. Momotaro Mikoshiba will be played by Jerry Jewel (Kyo in Fruits Basket), Aiichiro Nitori by Josh Grelle (Ginoza in Psycho-Pass) , Miho Amakata by Caitlin Glass (Haruhi in Ouran Highschool Host Club) and Goro Sasabe by Christopher R. Sabat (Vegeta and Piccolo in Dragon Ball), among others.