Yakouchuu is an adventure game for the Super Nintendo, translating to Phosphorescent Animalcule. It is a sound novel that presents a narrative-driven experience similar to Chunsoft's Otogirisou and Kamaitachi no Yoru. Players assume the role of a captain navigating the ship Diana, making decisions that influence the unfolding story. A Game Boy Color port and a sequel for the N64 were released in 1999.
Yakouchuu is an adventure game. The title translates to Phosphorescent Animalcule (animalcule meaning a microscopic animal, a portmanteau of animal and molecule) and specifically to Noctiluca scintillans.
It is a `sound novel` in the vein of Chunsoft's hits Otogirisou and Kamaitachi no Yoru (localized as Banshee's Last Cry): the player reads a novel-like story as the text appears on the screen with a static backdrop and background sounds to set the scene. They also occasionally make choices which can determine the route of the story. Yakouchuu concerns the ship `Diana` and its captain, who is the player-named protagonist, and crew as it sets off on an inauspicious journey.
The game was ported to the Game Boy Color in 1999. The same year, it saw a sequel for the N64: Yakouchuu II: Satsujin Kouru.