Question 1

Where is Shinjuku Mitsui Building?

Accepted Answer

Shinjuku Mitsui Building is in Shinjuku, Tokyo, Japan. You can see its exact position from the map coordinates and the Street View link.

Question 2

Which scene of There's No Freaking Way I'll be Your Lover! Unless... does Shinjuku Mitsui Building appear in?

Accepted Answer

Shinjuku Mitsui Building appears in EP9 of There's No Freaking Way I'll be Your Lover! Unless....

Question 3

Can I visit Shinjuku Mitsui Building?

Accepted Answer

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

Question 4

Where was There's No Freaking Way I'll be Your Lover! Unless... filmed?

Accepted Answer

Anime and manga are not filmed the way live action is. Their backgrounds are painted from photographs of real locations, and Shinjuku Mitsui Building is one of those real places (EP9).