The boss of the Night-Siders. A woman. Since she is poor at group activities, she infiltrates the Day-Sider territory alone to carry out attacks. To facilitate this, she adopts a name and appearance that blend in with the Day-Siders. When she doesn't need to use the pseudonym "Kuragari," she uses her real name, "Luna." She wears Japanese-style clothing reminiscent of an Onmyoji and has extremely long black hair. She has a gloomy personality, suffers from incredibly low self-esteem, and is pessimistic. However, she possesses absolute confidence in her abilities alone. "Phalanx": Sorcery that summons dark spears from the night. By slashing through space with a dark spear, she can instantly turn the area into night, from which she can replicate more spears. The night interferes with the Day-Siders' spiritual arts.

The leader of the Day-Siders. A woman. Since she gets distracted when too many people are around, she usually infiltrates the Night-Sider territory solo to play pranks. To facilitate this, she adopts a name and appearance that blend in with the Night-Siders. When she doesn't need to use the pseudonym "Lantern," she uses her real name, "Onibi." She wears mourning clothes, carries a candle, and has extremely long white hair. She is a massive prankster who immediately acts on any funny idea she has. She treats everyone cheerfully, whether they are friend or foe. "Flame of Psychometry": Touching the flames Lantern creates imparts the "Day-Heart." The Day-Heart stimulates the instinct in both living and non-living things to act toward the day. If one is influenced too much, they become unable to disobey Lantern. The Day-Heart interferes with the Night-Siders' magic.

A common traffic jam seen in Day-Sider cities. It is severely congested, making travel take about five times longer than usual. As a solution, there is a period called "Idaten" for one hour a day where all cars can travel at 170 to 200 kilometers per second. Cars in this world are sturdy, so they can handle any reckless driving.

An energy drink widely distributed in the Night-Sider territory. Drink this, and you won't feel sleepy even at night. However, overconsumption leads to weight gain, poor body temperature regulation, and a decline in memory.

Since the Day-Sider territory is always daytime, it is very hot. One must take proper precautions against heatstroke.

Since the Night-Sider territory is always night, ramen shops operating late at night are lined up every 20 meters. Rumor has it that delicious ramen stalls can occasionally be found on the roadside.