It was originally published in the December 1970 issue of the manga magazine Bessatsu Shōjo Comic under the title Yuki to Hoshi to Tenshi to... (雪と星と天使と, transl.

The story is a loosely adapted and condensed version of Takemiya's later manga series Kaze to Ki no Uta, and follows the relationship between a Roma teenaged boy and the son of a wealthy family.

Serge Battour (セルジュ・バトール, Seruju Batōru),[a] the teenaged son of a Roma fortuneteller, regularly visits an abandoned mansion to spend time in its sunroom.

[7] Shōjo stories in general were marketed to an audience of children, were focused on uncomplicated subject material such as familial drama or romantic comedy,[8] and favored Cinderella-like female protagonists defined by their passivity.

[9][10] Over the course of the 1970s, a new generation of shōjo artists would emerge who would introduce a greater degree of narrative and thematic complexity to the genre, collectively referred to as the Year 24 Group.

[1] By having one of the central characters be a young girl, Sunroom Nite was able to "barely maintain the appearance of a shōjo manga",[1] with Takemiya remarking that Angel's inclusion "made it easier to tell the story.

Takemiya submitted a manuscript of the finished manga under the same title as the previously announced one-shot, but with completely different content, immediately before the publication deadline for Bessatsu Shōjo Comic.

[1][14] Her editor Junya Yamamoto [ja] called Takemiya to the Shogakukan offices, where he expressed anger that the content was different from what had been discussed, but ultimately permitted the manga to be published as-is because there was no time to revise it.

[1] In 1976, Asahi Sonorama published an anthology of short stories by Takemiya titled Sunroom Nite under its Sun Comics imprint, which contains the titular one-shot manga.

[28] In 2010, eBook Initiative Japan [ja] released an e-book anthology titled Sunroom Nite, featuring the titular one-shot and five other short stories by Takemiya from the early 1970s.

[30] In their analysis, Ishida attributes the positive reader response to interest in the new theme of shōnen-ai, as well as the quality of the story itself, including its focus on the internal conflicts of the characters.

[32] After the publication of Sunroom Nite, Takemiya says that was separately contacted by manga artists Jun Morita [ja] and Ryoko Yamagishi through the editorial department at Shogakukan, both of whom had read the story.

[1] Sunroom Nite played a significant role in establishing male–male romance as a discrete category of manga, and became a precursor to the modern genres of yaoi and boys' love (BL).

[36] Ishida similarly evaluates the series as an influential work that served as a starting point for manga about romance and sex between men created by women for a female audience.