Supernova made their Japanese debut in September 2009 with three singles released over three consecutive weeks: "Kimidake wo Zutto", "Hikari", and "Superstar ~Reborn~".
Choshinsung memulai debut Jepang mereka pada September dengan tiga singel yang dirilis selama tiga minggu berturut-turut: "Kimidake wo Zutto", "Hikari", dan "Superstar ~Reborn~".