If you are searching for a technical paper in a different field, "cross day" is also a common term in:

: Fandom's School Days Wiki mentions early technical analysis and Sekai Project blog posts that broke down the dramatic improvements in the scripting engine of Cross Days compared to its predecessor, School Days . Contextual Uses in Other Fields

: A master's thesis titled "User and media perception on game design anti-piracy measures" by researchers at Uppsala University analyzes Cross Days as a primary case study. It examines the public's reaction to the game’s controversial "endogenous DRM," which functioned more like malware than traditional protection.

: The article "Video Game Piracy as Viral Vector and National Security Threat" by Andrew Moshirnia discusses the "Kenzero" Trojan that was bundled with pirated copies of Cross Days . The paper details how the malware collected personal data, browser history, and screenshots of users attempting to download the game for free, eventually posting the info publicly on a blog.