The round watermark area is the hit box
Resized to 88% of original (view original)
Artist's commentary
When the Yorigami Sisters fire out danmaku in the original STG,
Shion shoots invoice-type bills,
while Jo'on shoots currency bills.
There's already someone who uses talismen.
The kanji for paper currency and talisman are the same (お札), but pronounced osatsu and ofuda, respectively