Leaf Games' PC-98 title Shizuku has been translated into English by Her-Saki, just in time for its 30th anniversary.
Released exclusively in Japan at the start of 1996, the game was apparently the first to use the genre term 'Visual Novel' and marked the genesis of Leaf's 'Visual Novel Series'.
The storyline is a mix of horror and sexual content, making this a resolutely 'NSFW' release. It would gain a PC release in 2004.
Here's the synopsis, translated by The Visual Novel Database from the game's Japanese release:
The last few days have flown by as if I were floating in a bizarre, viscous sands of time. I had a peculiar delusion that every day the same time was repeating with the same pictures. It has been a string of tedious days with no signs of change for the better. Before long, I realized that all of the sounds and colors were leaving my dull world. I had given up on my uninteresting reality and was gradually stepping towards the world of madness...
And when one day, a girl in my class went insane. She sprang up straight from her seat, as if she were a machine, and abruptly began shouting obscenities. At the time when the teacher held her mouth, her face had become covered in blood from fresh wounds. It was the girl's own nails that were digging into her skin. While the rest of the class gasped at the scene, I just stared at the fresh blood, feeling that the real world was regaining its color...
After classes, one of the teachers in the school, my uncle, asked me to investigate this matter. So now I am starting the investigation with the assistance of one of the girls who has a connection to the case.
You can grab the translation patch here.