The world consists of Ship girls and humans, as for era, it is somewhere before the world war 1 of the earth of which we generally know of. The twist is that the world is conquered by white skinned people and their latest threats are monster girls are deep girls.

Ship girls are girls or woman who can transform into girls or ship at their will this is what normal humans mostly choose to believe. As newborn ship girls are pure and easier been influenced by other people. Ship girls are controlled by the navy academy to be educated to be loyal to the country.

Of course, Ship girls like a normal female human can fall in love and breed to make more ships. Unless the ship girl is released, normally they will gradually fall in love with their captain. Ship girls can be made through other hidden methods.

In this world, the highest decision making lies on the strongest ship girl in their faction due to ship girl war where there is a world war which many ship girls are dead. Due to a certain group of captains who want to collect all types of ship girls over the world by capturing the ship girls from other captains. The ship girls gather together and rebel against the humans, after that they control all the countries in the world.

Captains are male humans or rarely female who have used their bloodlines to build the ship girls also rarely ship boys through construction cubes which they can have shared vision with the ship itself, command them at will and etc. Generally, have a more supportive role like helping on decision making. Their power has weakened since the ship girl war as ship girls have successfully rebelled against the captains and managed to build a system that reduces captain into something like a slave/pet.

Deep girls (nicknames are deep sea, abyss) are same as ship girls but they first are known to man since man have/develop the abilities to travel on the sea through raft or boat. They dislike man travelling around their territories. They hate for man are further increase as the man have the skills to construct ship girls. The rest of the information is unknown.

Humans well, they are like humans on earth same as readers but a bit stronger due to labours like working in the farm, transporting of goods and etc.

Bloodlines which enable male humans to summon/construct ship girls and there is an entrance test to test up those bloodlines. Bloodlines considered potential are raise into higher ranks while those which are not favoured are ended up being cannon fodder.

Construction Cubes: A strange cube that uses one bloodline to construct ships in the construction building area, depends on one bloodline, normally the longer the construction time and more resources it requires to build means more superior ship have been constructed.

Lesser construction cubes: Construction Cube with 50% of its effect and it can only construct up to tier 1 ship

Greater construction cubes: Construction Cube with 150% of its effect and there is a 1% chance of building a ship that is different from a destroyer class.

Tri construction cubes: 3 construction cubes have been fused into one, no one knows what it will build into?

Instant Construction Drill has known as Instant Drill which has the power to speed up construction of the ship for 24 hours in construction building area, normally people use it as a fast and quick way to get more ship with less time waiting.

Construction Building Area (CBA) is a place where new ships that are born from captain bloodlines and materials.

Resources: sometimes are known as building materials, supplies and etc. The most common resources are wood(timber), metal, ammo (bullets, melee weapons like swords, sabre and etc, gunpowder, cannonballs), Gold, Coal. There is some alt history that has been written as there were some nations use rocks and silver as resources too.