Siren Commander, a mole in his own port

By chance, Luo Yun was summoned to another world by the Sirens and became their commander. But before he could start enjoying his new life, he was told to carry out a special undercover mission.
As the first male visitor to the isolated city of ship girls, Luo Yun needs to find opportunities to steal their confidential information, and even sell his body if necessary. Is there such a good thing?
Wait, if I don't successfully conquer them within a year, my life will be in danger? But there are hundreds of them!
No matter how reluctant Luo Yun was, he had to carry out this dangerous mission as his fate was closely tied to Siren's.
However, as his understanding of the ship girls gradually deepened, Luo Yun accidentally learned a shocking secret.
It seems that the owner of this port area is himself...