Watch on SFlix. Rumors spread about Haru, the feared brawler, as challengers line up to test him. One day, rival school Aokou is wiped out overnight. The culprit: Red Tengu, the strongest biker gang around. Soon after, Red Tengu’s charismatic leader Tesshin personally appears at Kiwakō. “Tomorrow. At the riverbank.” School pride, team loyalty, and manhood collide in a brutal showdown that stains the blue sky red.