Artist singing game theme song. Cassandra's long-awaited first album! This work is made up of 13 songs including 5 tie-up songs of the game. All songs have been written down by music producer Tani Arai. The second song [KINGDOM] is the lead song of the album. Gorgeous orchestration and pops beat and belcant singing. It is a song that can be experienced by Cassandra's "Pop Opera" that mixes pop and classical music. A comical song like a musical. Music incorporating a majestic choir that imitates a voice corps. Cassandra's vocal that separates pop singing voices and classical voices freely. "Pop opera" without a mistake hit from now on! It is! Listen as quickly as you can boast to everyone! It is!