Question 1

Where is Yamato Civic Gymnasium Maebashi?

Accepted Answer

Yamato Civic Gymnasium Maebashi is in Maebashi, Gunma, Japan. You can see its exact position from the map coordinates and the Street View link.

Question 2

Which scene of Blue Box does Yamato Civic Gymnasium Maebashi appear in?

Accepted Answer

Yamato Civic Gymnasium Maebashi appears in EP13 of Blue Box.

Question 3

Can I visit Yamato Civic Gymnasium Maebashi?

Accepted Answer

Yes. Yamato Civic Gymnasium Maebashi is a real place you can visit. Check what it looks like on Street View before you go.

Question 4

Where was Blue Box filmed?

Accepted Answer

Anime and manga are not filmed the way live action is. Their backgrounds are painted from photographs of real locations, and Yamato Civic Gymnasium Maebashi is one of those real places (EP13).