Little Blue Box, a Japanese pop rock group formed in 2010, was initially composed of five members but eventually consisted of vocalist hie and guitarist yui. The band is best known for providing theme songs for the Danball Senki video game and anime franchise. Their debut single "1 ドリーム / Great Future War" was released on May 4, 2011, marking their breakthrough in the industry. This single served as the opening themes for both the Danball Senki anime and its PSP video game adaptation. Throughout their career, Little Blue Box released several notable singles including "三位一体" (2012) and "2スピリッツ/レジェンド" (2012), which were also used as opening themes for Danball Senki series. Their only album, Brave Hero / ファイティングポーズ, was released on March 28, 2012. The band's final performance took place on February 16, 2014, titled "1ドリーム ～夢と希望の青い箱～" (1Dream ~Yume to Kibou no Aoi Hako~), following the conclusion of the Danball Senki anime series and with no further sequels announced.