Question 1

Where is Beach side House?

Accepted Answer

Beach side House is in Miyakojima, Okinawa, Japan. You can see its exact position from the map coordinates and the Street View link.

Question 2

Which scene of Grand Blue Dreaming does Beach side House appear in?

Accepted Answer

Beach side House appears in EP10 of Grand Blue Dreaming.

Question 3

Can I visit Beach side House?

Accepted Answer

Yes. Beach side House is a real place you can visit. Check what it looks like on Street View before you go.

Question 4

Where was Grand Blue Dreaming filmed?

Accepted Answer

Anime and manga are not filmed the way live action is. Their backgrounds are painted from photographs of real locations, and Beach side House is one of those real places (EP10).