A Gundam photo-novel that takes place during and after Zeta Gundam and into early Gundam ZZ. Details the story of a special Earth Federation Space Force task force, Taskforce Alpha, pursing and suppressing a small rebellion of former Earth Federation military officers.
Originally conceived as an animated television series that would serve as a sequel to Gundam ZZ, the project was canceled in favor of Char's Counterattack. Japanese hobbyist magazine Model Graphix, with whom Gundam Sentinel was co-planned, reinvented the project as a photo-novel and serialized the story in monthly installments. Strong fan reaction in favor of Gundam Sentinel prompted merchandising company Bandai to release a line of model kits based on the series.
Gundam Sentinel is primarily known for launching the career of now-prolific mecha designer Katoki Hajime. Also, Gundam Sentinel is the only Gundam property that is not fully owned by Sunrise and Bandai. Due to their involvement in pre-production, Model Graphix holds a copyright claim on the series. This makes Sentinel the only Gundam series that Bandai must pay royalties on in order to create merchandising based on the property, such as model kits or video game appearances.