Kingdom Days is set in a kingdom neighboring Wonderland and was released on 5th September 2010. It is about a princess named Rose who is forced to flee her kingdom with her elf servant, Lewis, when it is attacked by a neighboring kingdom. They wander through a forest till they see on a castle and knock on its door and meet a king who will not let them stay unless Rose marries him in 30 days.

The game begins with a backstory for the player character, Rose. She is an orphan waiting to be adopted and meets a boy named Lewis. The boy helps her find her lost royal family from the Lunar Kingdom and he turns out to be her servant. More information about this is learned if the player dates Lewis in the game.

A war breaks out between several kingdoms and it becomes unsafe for Rose to continue living in the castle when it gets attacked by Cesathis soldiers. She escapes with Lewis to Hepcatsis Kingdom where they meet King Joseph.

Joseph turns the pair away until Lewis promises Rose's hand in marriage. Joseph accepts and the wedding is set to happen in 30 days, though he is absent for 15 days which makes it difficult to get to know him before the wedding day.