Japanese: 柱後ろ抱き縛り
Hashira (柱): Vertical wooden beam used in traditional Japanse houses.
Ushirodaki (後ろ抱き): Behind embracing.
Shibari (縛り): Tie.

Tying someone to an upright wooden pole (hashira) with the hands tied behind (ushiro), embracing (daki), the pole.

Alternative term: Hashira Kousoku (“wooden pole restraining”)

See also: Hashira shibari, Floating Bamboo