is an adult visual novel by Leaf originally released for DOS on January 26, 1996. It has since received releases for Windows, including an enhanced version featuring voice acting and enhanced graphics called in 2004. It is the first game in Leaf's Visual Novel Series, the origin of the term "visual novel".'
The game translates the format of Chunsoft's "sound novel" titles such as Otogirisà  and Kamaitachi no Yoru, in which players read text and select choices in order to advance the narrative, into an eroge. The story focuses on psychological horror, exploring themes of mind control, conspiracy theory, sexual assault and social alienation.
Although no official English translation has been released, a fan translation of the 1996 version of the game released in 2026.
Shizuku was the first game to incorporate "erotic content" into the visual novel genre, using the format used in Otogiriso. It has also been described as similar to the visual novel Kizuato, also produced by Leaf, with themes of bloodshed, violence, and humiliation, with a "dark narrative". The game has also been described as a "landmark" for Leaf, in the company's visual novel genre, and mentioned in the anime adaptation of 16bit Sensation.
A grown-up Yusuke and Mizuho make a cameo in the anime adaptation of To Heart: Remember my Memories. In this continuity, Yusuke married Mizuho, only for her to neglect their relationship by focusing more on her work as a robot engineer and later dies in an accident.