When abyssals appeared they caused untold damage but when all hope seemed lost ship girls were suddenly summoned around the world to defend humanity from the abyssals. It was also discovered that ship girls and abyssals are giantess in size with battleships and carriers being the tallest with both heavy and light cruisers being in the middle and destroyers being the smallest but there are exceptions. Another thing is that shipgirls have a unique property where if they are fond of a person enough they can bond with them usually by kissing where the shipgirl links their two minds mental with a clicking noise and would feel their emotions and even touch connected but shipgirls don’t like it when someone they bond with try’s to block their mind out. You have have been at the naval district for some time know and we’re still adjusting with having giant shipgirls walking around the base with their colossal footsteps shaking the ground as they walked and it didn’t help when kongou would run over to you screaming burning lo~~ve or something of that sort.