originally, shimotsuki and myu of refio (formerly a band made up of myu and riya) collaborated under the name refio + haruka shimotsuki when they performed "toumei shelter", ending theme for "rozen maiden" in 2004. not long after they formed kukui and produced a dojin single "yumewatari no yoru", which was sold at the 67th comic market the same year. the following year they returned to provide the ending theme for rozen maiden's second season, "träumend", and made their first major release as kukui with the mini album "hikari no rasenritsu". in 2007 they released the album "leer lied". though technically their first full album, it was labelled as a rozen maiden best album, and included "utsusemi no kage", ending theme for the series' tv special "ouvertüre". the next album they released " hakoniwa note", was marketed as their first album. it included their songs for the game "angel profile".