Sadako Yamamura
is the lead character in Koji Suzuki's novel "Ring", published in 1991. He is married to Shizuka Asakawa and they have a one-year-old daughter named Yoko. His best friend is Ryuji Takayama, a college professor and alleged rapist. After his wife's niece Tomoko dies and he comes across another boy who died on the same day on his motorbike, Asakawa tries to find out why, which then links him to a cursed videotape and the malevolent ghost Sadako Yamamura. After watching it, he is left with seven days to figure out how to break the curse.