Question 1

Where is Marunuma Onsen Kankoso?

Accepted Answer

Marunuma Onsen Kankoso is in Katashina, Gunma, Japan. You can see its exact position from the map coordinates and the Street View link.

Question 2

Which scene of Slow Loop does Marunuma Onsen Kankoso appear in?

Accepted Answer

Marunuma Onsen Kankoso appears in EP3 of Slow Loop.

Question 3

Can I visit Marunuma Onsen Kankoso?

Accepted Answer

Yes. Marunuma Onsen Kankoso is a real place you can visit. Check what it looks like on Street View before you go.

Question 4

Where was Slow Loop filmed?

Accepted Answer

Anime and manga are not filmed the way live action is. Their backgrounds are painted from photographs of real locations, and Marunuma Onsen Kankoso is one of those real places (EP3).