kaisen higarashi 16 years old high school student from Kyoto and he need tuition that why he working now as part timer as Lifeguard at the beach !
and suddenly two people suddenly drowning he going to save theme it's seemed to be pulling from him and looked under the water he see like humanfish or something he panic so he quickly swam into the shallow but he he was already pulled down and he has lost consciousness and he woke up already in unknown island !
" AND THAT THE BIGGIN"