Squid Girl and Eiko pair up to join the beach volleyball tournament. With sights set on the grand prize of a 3D TV, the usual faces stand in their way: Sanae and Cindy, Gorou and Isozaki, Nagisa and Kiyomi.  Even the owner of the South Wind and the Idiots Three enter as the matches become chaotic!
Squid Girl's tentacles stop working.  Various treatments to restore them are unsuccessful and Squid Girl is at a loss. Finding the flapping things on her head also won't move and even her ink is weak, Squid Girl makes the decision to...
With no prospect of restoring her tentacles, Squid Girl has lost both her invader self and her pride as a squid.  Suddenly before her appears...?
But it's really strange that this devolution
happened so rapidly.
Es ist aber ungewöhnlich, dass die
 Rückentwicklung so schnell geschieht.
Pero es muy raro que la degeneración 
pasara tan repentinamente.
Pero es muy raro que la degeneración 
pasara tan repentinamente.
Pourquoi une dégénérescence
aussi brutale a-t-elle eu lieu ?
Mas é muito estranho que a sua involução
 aconteceu tão rápido.