Like his father Toshinari, Sadaie first learned Hosshoji-ryu calligraphic style, but he created his own idiosyncratic calligraphic style, which reflected his stubborn personality very well.
定家の書道は、父の俊成と同じく法性寺流より入ったが、強情な性格をよく表した偏癖な別の書風を成した。