The updated website also revealed the first key visual (pictured), which was created by animator Maki Fujii. A trailer was uploaded to the YouTube channel of Aniplex, but it is region-locked to Japan. The complete production staff and additional cast members were also announced.
Kokuhaku Jikkou Iinkai is a series that HoneyWorks initially created for Vocaloid songs. Various seiyuu later joined the project to voice the characters depicted in the music videos, which were uploaded to Niconico and YouTube. The music videos have 100 million cumulative views on both platforms. A light novel series, Kokuhaku Yokou Renshuu, featuring the characters has also been published since February 2014.