Aikido: Yoshinkan Aikido demonstration

Aikido Yoshinkan (養神館, Yōshinkan, lit. House for Cultivating the Spirit) is a style of aikido founded by Gozo Shioda (1915-1994) after World War II.

Yoshinkan Aikido is occasionally called a "hard style" because the training methods are a product of the grueling period that Shioda spent as a student of Morihei Ueshiba. It is also generally closer to aikijujutsu than so-called "soft styles" of aikido, and has sharper, more angular movements. The unusual emphasis placed on correct form rather than correct flow and timing further contributes to its image as a "hard style." However, the merit of such terms as "hard" and "soft" is generally believed to lie on the superficial level of describing a style's "feel", rather than saying anything about the heart of the style itself.

Source: Wikipedia