In 1987, Dragons closer Kazuhiko Ushijima was traded to the Lotte Marines for Hiromitsu Ochiai, and manager Senichi Hoshino chose Kaku as the new closer. Kaku was a huge success in the closing role, using his solid control and hard screwball to lead the Central League in saves in 1987 and 1988. The Dragons won the league championship in 1988, and Kaku received the league MVP award despite having to return to Taiwan during the season to mourn for his younger brother, who had died in a car accident.
