M3: The Dark Metal - Season 1 Episode 4 Danger, Do Not Mix

Akashi and the pilot candidates were dropped down onto a deserted island for mock investigation training in uncharted territory. While one condition for them to clear the mission was for "all members to gather in one location," Iwato and Raika fear the danger that Heito, who landed on the deserted island earlier than the others, possesses. While the candidates are enveloped in anxiety and terror beyond words, it was Sasame's singing voice that guided Akashi and the others.