YU-NO first launched for NEC PC-9801 in 1996, and was followed up with Sega Saturn and Windows versions.
Here’s a rundown of the story, via TV Tropes:
The story begins with the disappearance of the protagonist Takuya’s father, known to the world as an eccentric and controversial historian. Though he is presumed dead, Takuya soon receives a package from the supposedly deceased man containing an odd set of items the purpose of which Takuya does not recognize. After wandering about a little investigating, he winds up at the local landmark Triangle Mountain, which is a large rock of unknown origin that has scholars confused.
While at Triangle Mountain, Takuya first runs across a beautiful naked woman who after kissing him suddenly drops dead and vanishes completely. Confused, Takuya is then suddenly confronted by a former friend and colleague of his father named Ryuuzouji. With him is Takuya’s young stepmother, Ayumi, who appears to have no idea what is going on. After Ryuuzouji pulls a gun on Takuya and demands the odd package he received from his father, things take a turn for the bizarre as suddenly space seems to warp and Takuya is suddenly alone at Triangle Mountain.
Takuya arrives back home and makes a startling discovery: The device his father sent him is some sort of dimensional hopping device that allows a form of pseudo-time travel via alternate dimensions. After approximately 50 hours, Takuya will be looped back to the mountain at Triangle Mountain without his memories and be forced to explore yet another alternate world. On the bright side, your inventory of items is retained from previous loops, which is pretty much necessary since there are multiple items you need in one route that you can only acquire in another.
The game’s voice cast is as follows:
- Takuya Arima (voiced by Yu Hayashi)
- Kanna Hatano (voiced by Maaya Uchida)
- Mitsuki Ichijo (voiced by Saori Onishi)
- Mio Shimazu (voiced by Rie Kugimiya)
- Eriko Takeda (voiced by Yuu Kobayashi)
- Ayumi Arima (voiced by Kaori Nazuka)
- Other characters:
- Masakatsu Yuki (voiced by Yuki Fujiwara)
- Toyotomi (voiced by Takuya Eguchi)
- Kozo Ryuzoji (voiced by Taiten Kusunoki)
Platforms for the YU-NO remake have not been announced.