With the rest of the girls recovering from the beach party incident, Aika, Eri, and Karen are left to explore the destination by themselves. They use a sub to head to the depths where they find an underground base, complete with airport runway. Karen begins to recall things about the base, and leads the way to a lab area. As Karen is the key to opening the lab doors, Aika and Eri put her to sleep and unlock the lab, only to discover a large number of chambers and a bunch of clones that look like Karen. However, the clones are not friendly, attacking the two girls until Aika beats down most of them. Then a giant Karen arrives and beats up Aika. Aika retreats to wake up Karen, who communicates to the giant Karen to make peace, and they are able to leave.