Guilty Kiss is a sub-unit under Aqours. The group consists of three members, namely Sakurauchi Riko, Tsushima Yoshiko, and Ohara Mari. The group was formed in phases: On December 2015, six different configurations were offered to be chosen from. On January 2016, the unit compositions were revealed, and people were asked to submit names for them. On March 2016, the choices for unit names were revealed. On April 2016, the chosen unit names were revealed. Guilty Kiss' name was meant to symbolize the slightly grown-up and little devil-like image the unit has.