About

Enigma of Sépia, or EOS for short, is a mobile RPG gacha game launched in October 2024 by the company Unicorn Whale Technology Limited, The mobile game amassed significant popularity in early 2025 for having a large cast of female characters, which are directly modeled after famous male anime characters, leading to it being humorously dubbed "Rule 63 The Game."

History

Enigma of Sépia was officialy launched in North America on October 18th of 2024 for Android,^[1] as GameFAQs data shows. A trailer for the gacha was uploaded on YouTube^[2], describing the game as a "next-gen RPG with breathtaking world-building and revolutionary gameplay that lets you level up any hero to SSR+". The trailer's description also stated an IOS release for the game dating back to February 14th, 2025. The video (seen below) received roughly 54,000 views and 816 likes in a month.

Reception

Enigma of Sépia large cast of parody characters inspired by notable anime characters became one of he game's strongest "features" to attract players, as The Gamer^[3] tabloid wrote on February 3rd, 2025, "New Gacha Game Gives Luffy And Other Iconic Anime Characters Waifu Makeovers.

Online Presence

The game started to get noticed on January 26th, 2025, after posting on X^[4] a gender-bend version of Chainsaw Man main character Denji, calling the character "Denise." The tweet amassed over 17 million views and 7,800 likes in a month.

Netizens started to question the legality of the reversed gender characters parody, leading to some jokes calling it “Rule 63 the game,” like X^[5] user @Zahylon tweet (seen below) shared on February 3rd, 2025, which received roughly 89 views and 5 likes.

On February 24th, 2025, YouTube^[6] user Xcel Blaze posted all the anime character references found on Enigma of Sépia, which amassed over 4,500 views and 143 likes in a day;

Various Reactions

Search Interest

External References