[2] A manga adaptation titled Twin Princess of Wonder Planet: Lovely Kingdom by Mayuki Anan ran in Ciao to promote the series, which was licensed in English by Chuang Yi for Southeast Asian distribution.

Fine, Rein, and the other princesses and princes leave the Wonder Planet to attend the Royal Wonder Academy, to earn their certifications to become the kings and queens of their kingdoms.

During the school orientation, the vice principal presents the Soleil Bell, which will only ring if the chosen Universal Princess touches it.

Birthday, the original designers of the Wonder Planet and the characters, launched a concept webpage in 2003 in hopes of marketing their ideas to companies.

[6] Throughout the series' run, the production crew held Princess Party events in real life to promote the show, offering collectable keychains with crests of the seven kingdoms.

After the show's run, it was followed up by a direct sequel titled Twin Princess of Wonder Planet Gyu!, which aired on TV Tokyo from April 1, 2006, to March 31, 2007.