Maeterlinck no Aoi Tori

On a cold Christmas Eve, two siblings remain in their home as their mother falls ill. Unable to sleep, they witness the arrival of a mysterious spirit named Berylune, who tells them about the existence of other worlds. Guided by Berylune and joined by their transformed pets and other spirits, the siblings embark on a journey to find the blue bird of happiness in order to save their mother. During their travels, they encounter unusual and fascinating locations. Eventually, they must confront a spirit of darkness to achieve their goal.