|Aliases||Submarine I-401, The Blue Steel|
|Species||Android (Mental Model of a Submarine)|
|Voiced by||Mai Fuchigami|
|Debut Episode||Awakening Arc, Episode 2|
Iona is a guest character that debuted in the Wooser franchise on Awakening Arc, Episode 2 with a brief cameo. However, she returns in Phantasmagoric Arc, Episode 6 alongside fellow show-mates Kirishima and Haruna.
Iona is originally from the Arpeggio of the Blue Steel franchise as a main character. She is one of the oldest Mental Models of submarines in the world and has experience with blending in to human society to the point of being indistinguishable until a point where she has to use her abilities.