Nagare Hisui, the Fifth Green King known as the Ever-Changing King, founded the Green Clan JUNGLE. His messy neck-length dark green hair features bangs obscuring the left side of his face, framing blue eyes that shift to a green glow in his left eye when using his powers. A critical injury during the Kagutsu Crater Incident destroyed his heart; a green aura now functions as his life-sustaining power core. He relies on a technologically equipped wheelchair, featuring colored buttons and a digital pad, and wears a teal straitjacket-like restraint to control his volatile powers. Releasing his full abilities causes this restraint to rip away, revealing white or black flowing outfits and transforming his hair to white. His personality blends childlike idealism with strategic manipulation. He genuinely pursues a world of equal power and freedom, accepting this may lead to natural selection. Yet, he readily endangers clansmen for his objectives, exemplified by activating a bomb near Douhan Hirasaka. Nagare maintains a familial bond with his top-ranked JUNGLE members—Sukuna Gojo, Yukari Mishakuji, and Tenkei Iwafune—treating them with respect and informality, supporting Sukuna's gaming interests or planning celebrations. Lower-ranked followers, however, are viewed as expendable. He demonstrates intelligence in adapting plans after setbacks, such as his defeat by the Gold King. Nagare grew up in a reserved but loving household. During the Kagutsu Crater Incident, he ignored evacuation warnings to play video games with friends, witnessing the Damocles Down event that killed everyone around him. Cement debris pierced his heart, but his simultaneous awakening as the Green King summoned his Sword of Damocles, preserving his life. Tenkei Iwafune discovered him in the aftermath, becoming a father figure. As an adult, Nagare challenged the Gold King, whom he considered the "final boss," and suffered defeat. This loss spurred him to create JUNGLE, seeking allies to harness the Dresden Slate's power and redistribute abilities globally. He later orchestrated events to draw out the Silver King, capturing Anna Kushina for her divination abilities, and declared war when the Silver King refused his alliance. In the spin-off "The Idol K," Nagare is reimagined as the head of an idol agency competing with agencies run by other Kings, focusing on comedic interactions and differing philosophies about idol management.