Kantai Collection started in 2013 and is a super popular naval fleet simulation game. April 23rd 2015 marks the exact day of their 2nd anniversary. There were a lot of 2nd anniversary images on KanColle submitted to pixiv! Check out these illustrations that are full of celebration and love for KanColle.
For more Kantai Collection 2nd anniversary images, check out this tag on pixiv: 艦隊これくしょん二周年記念リンク