Hanshoku Kyoushitsu -Joshikou Harem Nara Nani wo Yatte mo Yurusareru- by Softhouse-Seal - Adult Sex Game

The time is the near future.
Gene splicing has resulted in the birth of a new being.
This living plant has the ability to understand human language
and bears an open, kind and sincere soul.
The only problem is that it looks like a tangled mess of tentacles.
Genetic modification is declared a success, but
unsure how to proceed, the father of this creation decides to hide it in society.
Dubbed "Embryo-kun", the living plant is dispatched to a place where
it may be allowed to survive... such as an all-girl school!
They don't mind! A man is a man, IS A MAN!
So begins Embryo-kun's bizarre love life.