Attack on Titan: No Regrets

Shingeki no Kyojin Rivai Gaiden: Kui Naki Sentaku (進撃の巨人リヴァイ外伝「悔いなき選択」) is a spin-off manga illustrated by Hikaru Suruga and written by Gun Snark with a story based on the "A Choice with No Regrets" visual novel. This manga focuses on Levi Ackerman, and serves as a prequel to the main story by Hajime Isayama.

Kodansha USA released the manga starting in August, 2014.

That same month, a new OVA series based on the spin-off was announced. It consists of two episodes, bundled with the 15th and 16th volumes of the main series, and released on December 9, 2014 and April 9, 2015, respectively. Just like the main anime series, it was produced by Wit Studio with direction by Tetsurō Araki.

Reception
Aria magazine announced on the official website for Kodansha that it will be reprinting the prologue chapter of Shingeki no Kyojin Gaiden: Kuinaki Sentaku manga in the December issue on October 28, after the November issue sold out due to the extreme demand for the prologue chapter.

Trivia

 * The spin-off manga has the subtitle "Birth of Levi".