One Day: Haman's Deleted Affair (或る日 -H.D.A.-,H.D.A for short) is a one shot manga that serves as a prequel to Char's Deleted Affair, detailing a day in the life of Haman Karn during her stay at Axis. It was written by Hiroyuki Kitazume.
A teenage Haman Karn wakes up at 7:01 am, taking notice of the sunrise projection on the screen panel. Haman comments that as a spacenoid she has never seen a real sunrise, and also that as a female officer she is stationed in a private room in one of the older sections of Axis. Haman sleepily grooms herself, as she remembers she stayed up late last night discussing strategic simulations, and while eating breakfast reveals that the old block she is staying at is a military complex and as such it does not have enough room for the families there, which is why Haman and her sister have separate rooms. Haman then disscusses some of the daily routines at Axis: the breakfastes consist of only the essentials with fresh food only being served once a day, muscle strengthening excersises being held every morning in the gym to prevent muscle loss due to the zero G. From there there is a study period for the teenagers in the new schools in the section called Mauser, though Haman takes classes on her P.C. in her room. Having finished the basic curriculum, Haman studies political science and military affairs for officers, despite it being off limits, though she received approval from her father. She is then contacted by her sister Selena, who convinces her to go the mall in the newer sections. Haman narrates that the mall is full of people as they have received there first shipment of goods in three months, and that since Side 3 is under the Earth Federation's watch, it is hard to ship goods to Axis. Haman also comments that while it is easy to find women's clothes, it is not easy for her as she usually does not find anything that matches her taste. Before heading home, Selena spots an arcade and wants to go in, though Haman realizes the arcade is actually an MS simulator; inside an arrogant boy has maintained a winning streak and challenges anyone to try best him, to which Haman steps up. The boy chooses a MS-14A Gelgoog while Haman selects a MS-09 Dom, to which the boy mocks her for picking an outdated MS. Despite the technological disadvantage, Haman dodges all of the Gelgoog's beam fire, so the boy pulls out a beam saber, deciding to switch to close combat. Haman easily impales the Gelgoog using the Dom's heat rod and wins the match; the boy, identifying himself as Mashymre Cello, is shocked that he lost, but is more shocked to see he was beaten by a girl; later that evening, Haman finishes showering and comments that while she did not find any clothes she still had fun. Recalling Mashymre's blushed face upon meeting her, Haman says to herself "one day I will...", with herself blushing as she says it, implying a romantic interest in Mashymre.