Data West is a bit of an odd company, which has nothing at all to do with Data East. Data West started in 1984, making visual novels and adventure games for obscure PC hardware, like Fujitsu's FM Towns.
They were also responsible for the cult side-scrolling shooter series Rayzanber for the FM Towns and PC Engine, the last of which, Rayxanber III, was released for the PC Engine Super CD.
Brave Prove, a PlayStation ARPG, was perhaps Data West's most important later release, which you can see some info on here. Though the company released some small PC titles through to early 2002, Data West has since abandoned game development in favor of networking solutions, and other tech-related areas, having expanded as far as Thailand. You can see Data West's full games page here.