Ruone

Ruone (루원), born Takehata Kai on June 17, 2004, is the Japanese vocalist and dancer in AmbiO. Before entering the group's official debut arc, he had already built a small but useful recognition base through MAKEMATE1, where he competed under the name Kai and showed the polished movement style that still shapes his idol profile now.

That pre-debut visibility gave Ruone a different entry point from some of AmbiO's other members. Instead of arriving as a total unknown, he stepped into the group with a survival-show backstory, then carried that momentum into the late-2025 pre-release sequence of Runnin', I Wish, and Click. The full debut came on March 18, 2026 with Boys Be Ambitious, where his lighter vocal color and more fluid dance line helped broaden the team's stage palette.

Ruone matters because he gives both AmbiO and E Entertainment a clearer Japan-facing bridge without reducing him to a market role. He is one of the members who makes the group's multinational concept feel lived-in rather than cosmetic, and his trainee-to-survival-show-to-debut path gives AmbiO a stronger narrative depth than a standard rookie launch.