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.
The marine geologist 
Professor Nonko Yachigusa.
الجيولوجيّة البحريّة الأستاذة نونكو ياتشيغوسا
Dr. Nonko Yachigusa.
Sie war Meeresgeologin.
Nonko Yachigusa,
doctora en geología marina.
Nonko Yachigusa,
doctora en geología marina.
Nonko Yachigusa,
spécialiste en géologie marine.
Sì, Nonko Yachigusa,
professoressa di geomorfologia degli oceani.
A Dra. Nonko Yachigusa, geóloga marinha.
Профессор морской геологии
Нонко Ятигуса.