A tomboy, childhood friend, and next door neighbor of Kio. Since she was young she wanted to join the CIA, where her room is filled with listening equipment and guns. She was in the CIA recruitment program operating under the supervisor codenamed JACK, but believes she lost this after helping rescue Eris so lives at the Cathia Embassy. She has feelings for Kio, but believes he sees her as just one of the guys, so roots for Aoi to get him before "that alien steals him away". She wears a watch with a noticeable scratch on it.

After moving into Kio's house, her dormant feelings for him begin to resurface, especially after realizing that the only reason Kio treated her like one of the guys was because he was under the mistaken impression that Manami had a boyfriend named "JACK" that he would overhear her talking on the phone to sometimes.

Manami has a personal asisstroid named Yun Fat (most likely named after Cho Yun Fat). He has black hair, as opposed to the usual reddish-orange, wears a black suit and a pair of sunglasses with a cigarette, and attacks with a pair of energy pistols.