* Story
In the famous "water city" of Somden, a noxious gas began to billow from a rivercave.
The pollution destroyed half the town. Its people became lawless thieves.
Monsters made off with the last few good men -- the fathers of a local parish.
Sisters were dispatched as relief. One was the protagonist... but en route to Somden,
she was snatched by the monsters too.

Somehow she was saved but, from her head where the monster transgressed her
a strange flower had blossomed.
She made her way to the rivercave and roamed deep, save the fathers, to investage the flower......

* Game
Seed of Evil (Harahiraku Mashu, lit. "Devil Seed That Blossoms") by Hasoyua
is an RPG you can play how you like with customizable attributes:
sexual disposition, difficulty level, game over/no game over, and more.
You can also use the settings to skip messages and speed up battles.
Play your way, then play it again completely different; the player has autonomy.

- Character growth is two-fold by leveling up strength and increasing "filthiness"

- Losing battles will typically not end the game; the protagonist is captured instead...

- The contents of H scenes change if the protagonist is sensitive or pregnant, etc.
If you watch to the end you will gain access to other variations of a scene;
there's no need to play over and over to get variations.

- Approx 30 base event CGs, 400~500 total incl. variations (not counting pose art)

* Notes
Requires RPG Tkool VX Ace RTP (free)