Set after the time of Sakura Taisen 4 (game), Kanzaki Sumire, during a training session was noticed that her spirit power (rei-ryoku) has dropped tremendously, below levels required to pilot the Koubu-nishiki. She decides to retire from the Kageki-dan while she still holds the position of "top star" in the dai-teikoku gekijyou.

Official music video for Swan by the band Nabowa for their their 5th album titled "Drawings" being released on August 23, 2017. The song is entirely instrumental.