The game comes with two different story segments, South Island and Winter Lake.

South Island Edition
During winter vacation, Tina sees a TV program about the balmy southern islands and says that she wants to go to the ocean. Aoi proposes that they go visit her villa in the southern islands.

They immediately board a cruise ship to make the journey to the island as a group. However, on the way the weather turns nasty and the ship capsizes. Miyabi calls for help, but the radio is broken and proves of no use. They are left wondering if a rescue team will come looking for them.

Winter Lake Edition
During winter vacation, Tina sees a TV program about the warm southern islands and says that she wants to go to the ocean again. Kaoru points out that they just been to the ocean. With perfect timing, Mayu shows up to invite them to her vacation home for the holidays.

[From Rightstuf]