Suraimu-Chan

Suraimu-Chan (Slime-Chan) is a magical girl anime which had it's first manga in 1978 and it's first episode in 1981. The anime is about a girl named Sayaka who is infected with a wierd disease that turns her into a slime girl when she gets hit with water. Sayaka is not the only person with this disease, her friends Aimi, Aiya and Rinako also have this disease. being released in 1978, Suraimu-Chan was the first ever slime anime/manga.