Sanbangai Street sits just west of Shinjuku Station and is part of the dense network of narrow commercial lanes that define this section of the city. The area developed rapidly after the mid-20th-century reconstruction of Shinjuku and is now lined with small restaurants, curry shops, bars, and specialty eateries catering to commuters and office workers moving through the station district each day.

The nearby Shinjuku Post Office has long served as a recognizable landmark on the north side of the station, anchoring a neighborhood known for its mix of long-established storefronts and constantly rotating food businesses.