A month ago, World of Warships and the Aoki Hagane no Arpeggio series (or Arpeggio of Blue Steel) started a collaboration event. The event will currently have two missions/quests to obtain the two ships called Kongo and Myoko. Also Iona's voice (Mai Fuchigami/渕上舞) will be making a debut by talking to you for doing certain actions. The two missions will last until March 1, 2016. Each mission will have three stage objectives and you are required to use a Tier V ship or higher.
Kongo Ship and Iona I-401's Voice in Action
Anyway, after hearing about the collaboration (and liking the skin and voice), I'll be trying to at least obtain Kongo until the mission due date. However so far, I killed 4 cruisers out of 30 required for the first Kongo stage. Current ships I'm using for the first stage is Murmansk (obtained during Humble Bundle/closed beta phase) and a Kongo. Time to grind more...
More details: http://worldofwarships.com/en/news/common/arpeggio-blue-steel-debut/