The Dojo is a big brown building in the mountains. In here, Sensei trains penguins in Card-Jitsu by teaching them how to use the elements of fire, water, and snow. It can be accessed from the Dojo Courtyard. The Ninja Hideout is a similar place.
During the second stage of the mini-party Dig Out the Dojo, penguins could now access the building, however it was under construction at the time. It stayed like this until the party ended, and eventually it was complete for the Dojo Grand Re-Opening.
During the Dojo Grand Re-Opening, the Dojo was repaired and there was a gong show that would pop up every 4 minutes. The Dojo was also decorated for the occasion.
Mid-way through the Water Party 2017, the Dojo Grand Re-Opening ended. This was when the Dojo was decorated for the party. The room featured a pool with Octi the Octopus laying in it. A banner above the Dojo said: "Pool Party at the Dojo!!".
At the Halloween Party 2017, the room was darkened, and was decorated with streaming pumpkin lights, candelabras and jack-o-lanterns.
During Operation: Blackout, the skies were darkened outside due to the blockage of the sun. The windows were made dark to reflect that.
For the Christmas Party 2017, garland was placed around the walls and snowflake decorations hung from the ceiling. A bonsai tree was placed on the left side of the room.
From September 25, 2017, to December 27, 2017, the Dojo was given an update. Some decorations from the Dojo Grand Re-Opening came back, along with some construction equipment. The text on the banner above read: "Improved Card-Jitsu experiences coming very soon!" meaning that fixes for some of Card-Jitsu's glitches and bugs were underway.
The placement and appearance of the door in the interior is inconsistent with its appearance on the exterior. From the outside, the door is a double door in the middle of the wall, but from the inside, the door is a single door on the far left.