I-400

As one of Iona's triplet sisters, this dedicated submarine operative functions as a direct subordinate to Yamato. While her personality is notably reserved and quiet, she possesses exceptional skills as both a Mental Model and a subsurface vessel. Her unwavering loyalty to Yamato is matched only by her polite demeanor, making her an incredibly effective spy. Though she rarely speaks, her silent precision makes her an indispensable asset to her fleet's intelligence operations.