Hyochakusha

When 3 female high school students walk along the sea shore, they find a naked man laying down. They film him with their smartphones and the man says "Winner Take Nothing" before losing consciousness. The man is soon sent to the hospital, where he is diagnosed with having memory loss and he also drowned after swimming for an extended length of time. The man doesn't have any kind of identification. The only clue to his identity is a tattoo on his left ankle. The 3 high school students who found him uploads a video they filmed of him to social media. Due to the video, the man becomes famous.