Katasumi follows the demise of Kann

Katasumi follows the demise of Kanna and her classmate, Hisayo. They are feeding rabbits at school when Kayako, the ghost in the series and the curse's fulfiller, attacks them both.
4444444444 follows the death of Tsuyoshi, Kanna's older brother. Tsuyoshi comes to school to meet his girlfriend, Mizuho, and finds a mysterious ringing cell phone whose caller ID shows a strange number, 4444444444 (The number 4 in Japanese is a homophone of the Japanese character for "death"). The ghost of Toshio, Kayako's son and also one of the curse's fulfillers, appears and takes Tsuyoshi; his body is never found.