Question 1

Where is Kosaiji?

Accepted Answer

Kosaiji is in Chichibu, Saitama Prefecture, Japan. You can see its exact position from the map coordinates and the Street View link.

Question 2

Which scene of Botan Kamiina Fully Blossoms When Drunk does Kosaiji appear in?

Accepted Answer

Kosaiji appears in EP6 of Botan Kamiina Fully Blossoms When Drunk.

Question 3

Can I visit Kosaiji?

Accepted Answer

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

Question 4

Where was Botan Kamiina Fully Blossoms When Drunk filmed?

Accepted Answer

Anime and manga are not filmed the way live action is. Their backgrounds are painted from photographs of real locations, and Kosaiji is one of those real places (EP6).