In April 2006, Kusumi was cast as the voice actress for Kirari Tsukishima, the main character in the anime "Kirarin Revolution" and also released music under the character's name. Kusumi also made crossover television and concert appearances as Kirari on "Haromoni@" and "Oha Suta", leading her to become closely associated with the character. The success of "Kirarin Revolution" and Kusumi's real-world appearances as Kirari made her one of the earliest examples of the "idol voice actor" crossover that became popular beginning in the late 2000s. Throughout the show's run, Kusumi also released music as groups Kira Pika and MilkyWay with other cast members. Kusumi was named #17 in Daitan Map's "Top 50 Voice Actors of Popular Characters" in 2007.