Fantasy Guards Mansion, Attack!

The abyss and the deep-sea ship girl trouble the world that Chen Shu came to. What brought him to this world was a piece of steel, which allowed him to awaken the initial ship girl and turn it into a mark engraved on his hand, and the golden fingers would be unfolded one by one. Roses grow thorns to protect themselves, just like ship girls, so that the lovely ship girls can be treated tenderly by the world, so that there is no trace of the thorns on the roses, and they bloom in their own castle.