banshiryuu

Banshiryuu (幡紫竜, lit. "Pennant Purple Dragon") is a vertical-scrolling danmaku shoot 'em up that focuses on fewer, faster bullets, and is the third official game in the Seihou Project by "Shunsatsu sare do?". The game came in two major versions, released at Comiket 67 (Winter 2004) and Comiket 74 (Summer 2008) respectively. Both versions were released specifically for the Windows operating system.

https://en.touhouwiki.net/wiki/Banshiryuu

This tag implicates seihou (learn more).