By December 2202, General Serizawa begins serving in the post of general headquarters commander.During a joint battle between Earth and Garmillan forces against the Gatlantis Empire, he and Todo observe from UNCF headquarters.
These attitudes underlie his immediate and unprovoked attack on Garmillan vessels during first contact.They also drive his willingness to plot a mutiny in favor of the familiar Project Izumo against the Yamato mission and Queen Starsha's offer of unseen alien technology ("A World I Once Saw", "A Choice for the Future"). He is frustrated by the public praise given to Juzo Okita as a hero of the war with Garmillas, despite his own leadership and effort.He convinces Lieutenant Daisuke Shima to go along with Niimi's invitation to join the conspiracy.Once the mutiny is underway and Itou's security team has taken control of key sections, Hoshina helps to free loyal crew members from captivity, and arranges for the ship's chief medical officer to prepare Admiral Okita for duty.Serizawa becomes the chief proponent of the Izumo Plan to save human survivors from the devastation inflicted upon Earth by the war, and later the motivating force behind an illegal conspiracy to reactivate Izumo after its cancellation.
Despite his failures and crimes, he holds a position of high military power in the lead-up to the Gatlantis-Earth War.
With the war becoming increasingly hopeless over the next several years, the leaders of the Earth Federation placed Serizawa in charge of Project Izumo, which would enable a small number of humans to escape the solar system and settle a new homeworld.
Construction of an interstellar ship and other preparations were well underway when an unexpected messenger from the planet Iscandar arrived with a promise of new technology and a device to restore Earth's ruined environment.
Serizawa quickly defends the existence of these ships to Garmillas ambassador Loren Burrel at the ceremony, claiming that Okita did not have the authority to negotiate on behalf of all of Earth ("Tension--Get to the Lunar Embassy").
Many of Serizawa's most important actions are driven by an aggressive nature and by a distrust of the unknown.
Toru Hoshina is a security officer serving in the United Nations Cosmo Navy.