"Honoh no Tobira" (焔の扉, Honō no Tobira; translated as Door of Flames) is the fourth single of J-pop duo FictionJunction Yuuka.
This single includes an insert song of the anime Mobile Suit Gundam SEED Destiny, composed by Yuki Kajiura.
Coincidentally, the insert song of Gundam SEED (Gundam SEED Destiny's prequel), Akatsuki no Kuruma, was released exactly one year before this single.
This single peaked at #5 on the Oricon weekly charts[1] but is the first single in voice acting history to hit #1 on the Oricon Daily Rankings.
Source:[2] Oricon Sales Chart (Japan)