NBCユニバーサル・エンターテイメントジャパン
Kotoko's first official performance in North America was her highly successful American concert debut at Anime Expo 2005, soon followed by the Kotoko Lax Tour. In 2009, she wrote the song "Screw" for the Mamoru Oshii live-action movie "Assault Girls". The song was featured as the opening theme song to the console version of video game ', and her song "Hekira no Sora e Izanaedo" was used as the opening theme for the "BlazBlue" sequel '. Her 17th single "Light My Fire" was written by Ryo of Supercell and was used as the first opening theme to the 2011 anime series "Shakugan no Shana Final". She also appeared at the Animazement anime convention in 2012 and returned to the event in 2014. She collaborated with the band Altima in performing the song "Plasmic Fire", which is used in the anime film "Accel World: Infinite Burst". She collaborated with Luna Haruna on the song "SxW (Soul World)"; the song is used as the theme song to the video game "Accel World VS Sword Art Online: Millennium Twilight". In February 2018, she announced that she was returning to Geneon, now known as NBCUniversal Entertainment Japan. She released an album titled "Tears Cyclone" in June 2018.