Sokan — dual trunk
HTTPS://BONSAITODAY.COM/ARTICLES/BASICS/STYLES/SOKAN-DOUBLE-TRUNK-STYLE/ [BONSAI TODAY ]
The junction of the trunks at the base must be sharply “V”-shaped and not “U”-shaped.
One of the trunks dominates because of its length or thickness.
The smaller tree must be no more than two thirds the height of the larger.
http://www.why-bonsai.com/bonsai_twin_trunk.html [Why Bonsai]
When styling, to give added depth the secondary trunk should ideally be positioned slightly behind and not directly side-by-side to avoid a flat, two-dimensional image.
In classical twin trunks the secondary trunk emerges at the base of the main tree, forming an acute angle. The first major branch normally grows on the smaller trunk.