[Xero8420]

Originally Posted by Death Usagi

I guess you did not watch Arpeggio of Blue Steel. That's Iona, who is also known as I-401, a submarine.

Both shows had collaboration in game + anime, where in the KanColle game, the characters from the Arpeggio appeared, while in the anime of Arpeggio, KanColle characters appeared in the end art.

You could say KanColle and Arpeggio of Blue Steel are like cousins because they have similar concepts in story.

Spoiler:

Arpeggio also began collaborating with Wargaming to develop a game. And it's uncertain if KanColle is involved too.