Treasure (Lost Gods #1) by Megan Derr

Treasure - Megan Derr

M'rella gave us some Russian translations, and here are some Japanese ones :D 

Ningyo - mermaid
Taiseiyou & Taiheiyou - Atlantic & Pacific Ocean
Takara - treasure :D
Raiden - lightning & thunder
Arashi - storm
Shima - island

I liked this story. It took me about 20-30% to get into it, but after that I couldn't put it down (until 3am last night). Looking forward to the sequel!