A chibi series involving an aged down Kantai Collection Kaga (in previous KC-only comics by the artist, the aged down Kaga was explained as a Level 1 Kaga as opposed to a normal fully leveled Kaga) interacting with Azur Lane shipgirls, especially her Azur Lane counterpart (both carrier and battleship forms) in the role of a younger sister. It also predates KC Kaga's voice actress Iguchi Yuka also being named AL Kaga's voice actress on the Chinese server, so this is not made with a voice actor connection in mind.
Besides the Kagas, shipgirls featured in the series so far include: