Mezon Ikkoku (bangaihen): Ikkoku-tô nanpa shimatsuki (1991)

Yotsuya and Ichinose are enjoying a hot afternoon when they recall the time that the tenants of Ikkoku-kan and Mitaka go off on a cruise to party hard aboard Mitaka's new boat; however, the boat falls apart, and everyone is shipwrecked on a deserted island. With everyone up to their usual antics and shenanigans, what can happen in such a desolate place?