At today's Idoling!!! 4th Live concerts, it was announced that Idoling!!! #2, Rumi Koizumi would graduate from the group after the concert series due to poor health.
Koizumi was one of Idoling!!!'s original nine members who made their TV debut in October 2006, which makes her tenure with the group a little over two years. She has taken time off from the group and its TV show in the past due to health problems, and most recently, she was unable to perform at many of the Idoling!!! mini-lives during the Hot Fantasy Odaiba 2008-2009 Christmas and New Year's event at Fuji TV.
Koizumi seemed to be absent from the Idoling!!! 4th Live concerts, but, before the encore of the afternoon and evening Idoling!!! 4th Live concerts, a message appeared on the screen to announce her graduation, and Koizumi appeared on the stage to explain the reason behind it. She then joined her fellow Idoling!!! members in performances of NA・GA・RA, Omoi no Uta, Koi Gokoro, and Snow Celebration with a couple of MC segments between songs. The last three songs in the setlist were chosen by Koizumi herself, and the Omoi no Uta performance was apparently a special Koizumi-only version. After Koi Gokoro at the evening concert, the other Idoling!!! members got a chance to give their last messages to their departing friend.
Rumi Koizumi will remain under the Watanabe Entertainment talent agency and will continue working in other areas of the entertainment business. Idoling!!! will continue on as a 16-member group.