Question 1

Where is Osaru-no-yama?

Accepted Answer

Osaru-no-yama is in Nikkō, Tochigi Prefecture, Japan. You can see its exact position from the map coordinates and the Street View link.

Question 2

Which scene of The Future Diary does Osaru-no-yama appear in?

Accepted Answer

Osaru-no-yama appears in EP13 of The Future Diary.

Question 3

Can I visit Osaru-no-yama?

Accepted Answer

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

Question 4

Where was The Future Diary filmed?

Accepted Answer

Anime and manga are not filmed the way live action is. Their backgrounds are painted from photographs of real locations, and Osaru-no-yama is one of those real places (EP13).