In the near future, much of the world has been forgotten at the bottom of the ocean due to rising sea levels. Natsuki Ikaruga, who lives in a small town surrounded and stranded by the sea, is invited by a mysterious woman, Catherine, to search for a treasure in his grandmother's house who was a marine geologist. One day, he dives to the bottom of the ocean in a submarine and encounters a mysterious capsule with a girl sleeping inside. The girl was a humanoid so sophisticated that she could be mistaken for a human.
Call me "old lady" again and I'll 
send you to the depths myself!
نادِني بـ"الآنسة العجوز" وسوف
!أقذفك إلى الأعماق بنفسي
Se lo dici un'altra volta, ti mando a fondo!
Da próxima vez que me
chamar de velhota, eu te afogo!
Ещё раз так скажешь —
утоплю к чертям!