Question 1

Where is Umi no Pool?

Accepted Answer

Umi no Pool is in Atami, Shizuoka, Japan. You can see its exact position from the map coordinates and the Street View link.

Question 2

Which scene of Wash It All Away does Umi no Pool appear in?

Accepted Answer

Umi no Pool appears in EP8 of Wash It All Away.

Question 3

Can I visit Umi no Pool?

Accepted Answer

Yes. Umi no Pool is a real place you can visit. Check what it looks like on Street View before you go.

Question 4

Where was Wash It All Away filmed?

Accepted Answer

Anime and manga are not filmed the way live action is. Their backgrounds are painted from photographs of real locations, and Umi no Pool is one of those real places (EP8).