Using MediBang Paint Pro I made a flag based on the seal that appears on the tongues of Mizuki Yukikaze and Akiyama Rinko in Taimanin Yukikaze. This flag is both vertically and horizontally symmetrical. An idea of what flag would be hung on a certain building in a certain plaza in the lawless city of darkness known as Yomihara.
At the start of the game it will tell you how our heroines got into Yomihara. Yomihara is 300 meters under Tokyo and with a square area of 5 kilometers the sunlight never reaches, it's nighttime 24/7 and a city that truly never sleeps down there. The gates they enter are as tall as a 4 story building. Because it is 300 meters deep there are countless vents to bring the air down from the surface to make a breathable atmosphere for human occupation in the city. Buildings crammed tight connected to each other with electrical cables and pipes, neon signs on almost every corner, awning, and door it is a sleepless concrete jungle.
I wonder if the buildings themselves maybe what is supporting the ceiling preventing it from collapsing upon the city's denizens?