|Appears In:||Yu-Gi-Oh! Underground|
Kou Terumi is one of the main characters of Yu-Gi-Oh! Underground. He is the leaders of the group of Synchro Summon users, known as the Rings Gang, and is one of Yukito Ousama's rivals and former enemies.
Kou has blazing crimson hair that parts in two in the back and is said to resemble the head of a and wings of a phoenix. He also has a color matching beard on his chin. He has black eyes, though he usually keeps them hidden behind a pair of sunglasses. He is always dressed in a white button-up shirt, a red tie, with matching dress pants and shoes. His expression is usually a wide-mouthed smirk.
Kou has shown that while he is very calm and collective, he is also very childish. This is apparent in many of his actions, such as referring to Yukito as "a bratty kid" when he intends to annoy him, as he knows of Yuktio's complex about his age. This usually results in Kou sulking in the corner after being called "old man" by Yukito in retaliation. Kou is also very eccentric, with most of his actions being deemed "weird" or "strange" by even his fellow Rings Gang members. Such actions include using half of the power at Failinis to put on a laser light show in his office out of pure boredom.
Kou apparently inherited the Leader status of the Rings Gang a few months prior to the start of the Duel Wars from a currently unknown person. As such, he actively participated in the Duel Wars as acting commander of the Synchro Summon users, although he apparently lost at the hands of Yukito.
Kou seems to be able to easily read people by looking into their soul, or as he puts it, "looking at the color of their flames". Like most other Duel Gang members, he is able to use the Realist System.
Kou uses a Phoenix Deck, based on Synchro Summoning and the use of Ash Counters, which allow him to protect and/or revive his main Ace, Eternal Ash Phoenix.
- Kou's ideal voice actor would be Tomokazu Sugita.
- Kou's color scheme (black eyes, red hair, and dressing in white) are essentially Yukito's color scheme (red eyes, black hair, and dressing in black) inverted.