Red Ribbon Bulma is the best! Just the spanking was a bit harsher, and maybe Roshi treated her a bit more roughly...and even maybe spiked the drink to make her horny. Also Lolooki I think unless Yamamoto's doujins are direct sequels they're all their own universe.
In my opinion hottest Bulma yamamoto has ever drawn, I'm dying to see Roshi fuck her brain out since she appears in front of him in page 2. It helps tube top + shorts outfit is really hot.
I read the japanese version for translation purposes and found surprising that sometimes changes are substantial, english translate could be much better and makes me wonder if in the rest of his doujins the same happens.