Shikaku literally means blind spot or dead spot.
Shi 死 = death
Kaku 角 = corner / angle
In martial arts, this term has a deeper strategic and tactical meaning.
In combat, a tactical blind spot refers to the area that the opponent cannot see or control, their blind spot.
If uke is emotionally distracted, arrogant or inattentive, a mental blind spot also arises. This can be seen as an opportunity, an opening and a chance for a trained tori to end the confrontation.
In aikido, we strive not to leave any shikaku ourselves, i.e. to keep the spaces closed through present ukemi, and not to signal any specific intention. This creates an all-round awareness, a feeling for maai 間合い (the correct space-time structure) and mushin 無心 (the quiet mind). This awareness shapes the inner attitude, the kokoro no kamae 心の構え (attitude of the heart and mind).
