Subtle spookiness in Shinjuku isn’t promoting anything except fear in all who notice it.

The Shinjuku neighborhood is just about the most crowded place in all of Tokyo. It’s home to the world’s busiest train station, used by over a million passengers each day on their way to the district’s skyscrapers packed with offices, government facilities, shops, and restaurants.

Because of how many people pass through the area, advertising space in Shinjuku is highly coveted, with many marketers bringing their A game to promotions for the neighborhood, like a collection of every Yu-Gi-Oh! card ever printed or a giant gift-giving kitty cat. One advertiser in Shinjuku, though, has opted not for nostalgia or cuteness, but for subtle, easily overlooked terror.

The above video, shared by Japanese Twitter user @whip_bouya, shows an intersection just west of Shinjuku Station, with a building housing the local branch of the Kaleido pachinko parlor chain at the right edge of the frame. Like most buildings in Shinjuku, the walls are covered in signage, but as the camera zooms in, mixed in among the ads for karaoke and currency exchanges is a tall, brightly lit sign with an extreme close-up of a disturbingly dark eye, silently staring out at the city.

What makes the sign even more disturbing is that no one has any idea what it’s for. There’s no accompanying text, and none of the building’s tenants are in any sort of creepy lifeless eye-related industries. However, one online commenter was able to determine what he thinks the photo is of, though it’s not any less unnerving.

Twitter user @sasisusesota thinks the Shinjuku sign is a cropped photo of an Ichimatsu ningyo, a traditional type of Japanese doll. Moreover, he thinks it might be a specific doll offered through Yahoo! Japan Auctions some time ago, with the last known high bid being 2,100 yen (US$18.90).

The way pedestrians in the video seem completely oblivious to the sign makes it all the more unnerving.

But while there’s a popular explanation of what the sign is showing, there’s still no explanation as to why. Some brave souls jokingly offered suggestions that it’s a promotion for an as-yet unannounced new branch of the Ring or Attack on Titan multimedia franchises, but neither of those pop culture juggernauts would go so low-key in their advertising. If there’s one thing to be thankful about, it’s that the doll face hasn’t always been present on this building, as shown in older photographs of the intersection.

However, that just leaves us even more terrified, since now we don’t know where it’ll show up next.

Source: Twitter/@whip_bouya via Hachima Kiko
Insert images: Yahoo! Japan Auctions/Nagasm, Pakutaso

Follow Casey on Twitter, where he’s glad the SoraNews24 office is on the other side of Shinjuku from this sign.