Being a Gunpla built only for simulation purposes, the GPB-X80 Beginning Gundam has a very unique design with 4 vents on its face plate and a beam like V-fin on its head. The Beginning Gundam and the GPB-X78-30 Forever Gundam are considered brother units. The Beginning Gundam utilizes the I-field-based propulsion system similar to SYSTEM ∀-99 (WD-M01) ∀ Gundam with various triangular-shape parts as I-Field emitters. This gives it exceptionally high mobility despite Haru not building it properly.
The Beginning Gundam's performance is much lower during the first Gunpla Battle; this is because Haru, being new to Gunpla building, assembled it without painting, and leaving details unfinished. It became much stronger after Haru rebuilt it with greater expertise. The Gunpla itself is armed with nine beam sabers for close combat. Six of these are stored in the backpack, and the other three stored behind its shield. Three of its beam sabers can be held in each hand in a claw-like fashion. The Beginning Gundam is also equipped with standard weapons like a beam rifle and shield.
In 2009, after seeing the 1/1 scale RX-78-2 Gundam at Odaiba, Haru Irei wanted to buy a model of the Gundam, but ended up buying the Beginning Gundam instead after it fell off a shelf. The model was apparently one-of-a-kind, being unavailable for purchase through any other channel.