Shiitagerareshi Koushu no Koufuku na Konin Hitojichi Hanayome wa Futari no Ou ni Chouai sareru

Princess Suiren has the power to materialize paintings, but she lost her supernatural powers and grew up in an oppressed environment. Due to a plot by her half-sister, she is forced to marry the king of the land of Honoo, a land that is the source of terrifying rumours. She is frightened after hearing the tales of the king brutally murdering her parents and siblings, but what awaits her in marriage is a peaceful life without the king. While strolling through the harem, Suiren meets a simple, gentle young man named Kou. The two grow closer as they discover they share a common hobby of gardening. However, on the night of a banquet hosted by the king, Kou appears, revealing his true identity as Honoo's King, Kouten. Confused, Suiren then uncovers another secret about Kouten...

(Source: Kadokawa, translated)