«Vertical Square» is activated with a powerful stamp. The first strike of this Sword Skill is a vertical slash from an overhead position with little backward motion, similar to the 1-hit «Vertical». This slash is followed by two upward vertical slashes. Finally, the skill is concluded with a full-power downward slash from an overhead position. Similarly to the «Horizontal Square», a square, drawn with the four hits of this skill, continues to spin as it dissipates.
Yuuki used this skill against a Gnome player who was blocking the way to the 27th FloorLabyrinth's boss room. The Gnome was blown several meters away and his hit points dropped to the red zone after he was hit with this skill.
Vertical Square is one of Kirito's favourite Sword Skills.
The first season of the anime portrays Vertical Square as more of a diagonal or even horizontal square, despite it having "vertical" in its name.
In the anime adaptation of Calibur, Kirito used Horizontal Square instead of Vertical Square.
A modified version of «Vertical Square» was included in the updated version of «Dengeki Bunko Fighting Climax», known as «Dengeki Bunko Fighting Climax Ignition», as a special move used by Konno Yuuki.