Akaneiro ni Somaru Saka: Hardcore  

Akane Iro ni Somaru Saka Hardcore OVA, Akane-iro ni Somaru Saka OVA, Akasaka OVA, あかね色に染まる坂 Hardcore, Akaneiro ni Somaru Saka OVA, Akane-iro ni Somaru Saka Hardcore, The Hill Dyed Rose Madder OVA

Everybody goes on vacation to Ayanokoujis private island for fun in the sun. Hilarity ensues.