 The single’s title track was used for the opening of anime "Black Butler" and the release was also available in four versions, one which was a special Kuroshitsuji version featuring the two main characters on a cardboard sleeve.Their debut concert at Nippon Budokan sold out in under two minutes in November 2008.Their next single, titled "2°C me no kanojo" (2℃目の彼女), came out in January 2009, and three months later "Uso" (嘘) debuted at number two on the Oricon charts and was also used as the 1st ending theme of popular anime "".