The first two chapters Mobile Suit Gundam MS IGLOO: The Hidden One Year War (機動戦士ガンダム MSイグルー -1年戦争秘話-) and Mobile Suit Gundam MS IGLOO: Apocalypse 0079 (機動戦士ガンダム MSイグルー -黙示録 0079-), released in 2004 and 2006 respectively, are shown from the Principality of Zeon's point of view; while the third chapter Mobile Suit Gundam MS IGLOO 2: Gravity Front (機動戦士ガンダム MSイグルー2 -重力戦線-), released from 2008 to 2009, explores the Earth-based phase of the One Year War from the Earth Federation's point of view.

Taking place at roughly the same time as the original Mobile Suit Gundam, MS IGLOO follows the exploits of the Principality of Zeon's 603rd Technical Evaluation Unit, a special crew of weapons development researchers.

Stationed aboard the former civilian cargo ship Jotunheim (named after the land of the giants in Norse mythology), the unit field-tests various prototype weapons for combat use under the supervision of Engineer Lieutenant Oliver May.

With the outbreak of the One Year War, the Principality of Zeon forms the 603rd Technical Evaluation Unit, a team of soldiers, technicians, and engineering specialists in charge of assessing various prototype weapons aboard the Jotunheim, a civilian cargo ship refitted and enlisted for military use.

Ensign Werner Holbein, an arrogant naval officer who boasts a proud maritime family tradition, is assigned to the Jotunheim to pilot the mobile diver unit Ze'Gok.

Just as Gihren Zabi proudly announces to his troops the decimation of the Federation fleet by the Solar Ray, the 603rd receives its latest prototype weapon — the massive Big-Rang mobile armor.

Unknown to others, Barberry, who loses every subordinate in previous engagements, is frequently haunted by a spirit called Shinigami, who patrols the battlefield collecting souls of fallen warriors.

Instead of doing so, Colmatta approved Yandell's mad plan to launch a night assault on the oncoming Zeon force, which Snell leads.

Though Operation Odessa is proceeding, the 44th Hybrid Brigade suffers setbacks after its advance is bombarded by artillery fire from Zeon's Dabude-class land battleships.