Marriage Royale began as a reader-participation game in the January 2006 issue of ASCII Media Works' Dengeki G's Magazine sold on November 30, 2005, where the profiles of two girls, Minato Daiba and Minami Umeda, were supplied for the reader. After reading the profiles, the reader could illustrate what they wanted the girls to look like, and send it in; out of all the entries, two were chosen for each girl, and the attributes of both were combined to create a single character design illustrated by either Aoi Nishimata, or Hiro Suzuhira. Both illustrators are from Navel, which is also known for producing the visual novels Shuffle!, and Soul Link. Every three months, two new profiles were published, and this pattern continued until the fourth round with eight girls at the time. The second round introduced Komachi Akita, and Otoha Shinjo; the third round brought in Miyako Asakura, and Yamuko Hidaka; and the fourth round had Sera Saeki, and Asahi Sanjo. On July 30, 2007, four more profiles were published, with the same rules applying as with the previous rounds; the fifth round covered Ena Tenryū, Iyo Uwajima, Ebino Hamayū, and Uruma Nago. Aoi Nishimata has provided illustrations for Miku, Minami, Komachi, Yakumo, Sera, Iyo, and Ebino; Hiro Suzuhira drew Miu, Minato, Otoha, Miyako, Asahi, Ena, and Uruma.
The short stories themselves are more or less vignettes where each one gives a very brief glimpse of a scene between the protagonist, and the given heroine he is with in the story. The stories are accompanied by illustrations of the given heroine, and are drawn by either Aoi Nishimata, or Hiro Suzuhira depending on which artist originally drew which girl. The first batch of stories, serialized between the May 2006 and March 2007 issues, was under the collective title Girl's Heart, and contained eight chapters, one for each of the first eight heroines. A second batch under the general title Dearest Stories started serialization in the October 2007 issue.
The Marriage Royale manga, illustrated by Koko Natsuki of Lime, started serialization in the April 2007 issue of Dengeki G's Magazine sold on February 30, 2007, published by ASCII Media Works. The first bound volume was released on October 27, 2007 containing the first eight chapters, published under ASCII Media Works' Dengeki Comics label; the fourth volume was released on May 27, 2009. The manga contains the eight girls from the first four rounds of the reader-participation game, and carries the same premise as with the game too.