Founded in 1985, JAST was the first established Japanese company that uniquely specialized in eroge. They gained prominence with their Tenshitachi no Gogo series, which are considered the first adult games with distinctive anime aesthetics. Notable adult software brands (such as FairyTale) started off as independent groups initially consisting of former JAST employees. The company became defunct in 2001.
Caution: Its ads must be taken with skepticism because they often lie unreleased titles eg Afternoon Angels 4 / Valzell are on sale.