In the Ju-on films, Takeo killed Toshio because he wrongly suspected that he was not his son, and was instead the product of an affair between Kayako and Kobayashi. In the American films, Takeo had to kill Toshio because he walked in on him killing Kayako.

In the Japanese films, Toshio is six years old at the time of his death. Meanwhile, in the American films, he was either seven or eight years old (the online newspaper article that Karen reads states Toshio's age as seven, but a link to another online article on the search engine she uses states Toshio's age as eight).