I've been waiting for more doujins that pair Mamizou with Kosuzu or Akyuu, and finally Pandain delivers. The plot is simple: Akyuu stumbles upon Mamizou and Kosuzu having sex, fully knowing that she's about to be next. They both have fun with Mamizou, and there's a general lewd air about the scene. My favorite part is that Akyuu and Kosuzu have large breasts! I love when Kosuzu is depicted busty!
The only issue is that I wish we got to see more of the actual threesome between the whole group. Right when it seems like the orgy is about to begin, the doujin ends. It would be great to have a sequel where the three ladies are losing themselves in each others' depravity.