"ai uta" was released as their third single on may 16, 2007. it debuted and peaked at #2 on the oricon daily singles chart. it debuted at #8 on the oricon weekly singles chart and eventually peaked at #2 in its sixth week on the weekly chart. the song was certified two million by the recording industry association of japan (riaj) for 2,000,000 full-track ringtone digital downloads ("chaku-uta full").