A crimson archway appears on the face of a cliff as the Yokosuka Line train reaches Kita-Kamakura Station. Painted in exotic, Chinese style, the "gate" and the tunnel it leads into look somewhat out of place in the quaint neighborhood. Despite its recognizable appearance, few venture to discover what it is as it is a little (if just a few minutes walk) off the more tourist areas.

Originally, the tunnel served as a shortcut to the station from the other side, where there was a villa. It was dug in the 1930s-1940s by the villa's owner for his daughter, who took the train from Kita-Kamakura to her school in Tokyo daily. After the war, he founded a kaiseki restaurant called Kō-kō-Tei, serving "Genghis Khan" (grilled mutton as it is referred to in Japan).

Naturally, the tunnel earned the nickname of Kō-kō-dō or "Hao-Hao Tunnel," as well as the "Red Tunnel Gate." Though the city council has officially (yet tentatively) named it "Yamanouchi-Miyashita Alley Tunnel," no one seems to refer to it as such.

Inside the tunnel, visitors can see that the tunnel is roughly dug, and covered all over with chisel marks. There is also a large hole on either side, now blocked by piles of concrete blocks, suggesting the presence of a hidden passage behind. These tunnels-within-a-tunnel were dug during the war to access the embrasures installed on the cliff.

The Kō-kō-Tei restaurant closed permanently in 2004 (or 2007 according to another source), but the tunnel has remained for years since, a shortcut often used by locals to reach the station. Today, the other side is covered with wild vegetation, giving it a rough, countryside look. Combined with the Chinese aesthetics, it feels like a surreal portal to another world, something in the spirit of Spirited Away.