Akihiro Okamura is a supporting character who works as a newspaper reporter and photographer for the Ryukyu Daily. He is a man in his late twenties or early thirties, characterized by a somewhat jaded and down-on-his-luck demeanor, and is often seen chain-smoking cigarettes. His personal history is deeply connected to his father, a photographer and war correspondent in Vietnam. As a child, Okamura saw a series of disturbing black-and-white photographs his father had taken, depicting a young girl killing soldiers, villagers, and grotesque monsters with a sword. These images have haunted him ever since, fueling a lifelong obsession to uncover the truth behind them.

Driven by this motivation, Okamura begins tracing the origin of a mysterious wine sample, which leads him to Vietnam. There, he witnesses Saya fighting a Chiropteran and manages to take several photographs of her, though he is soon caught by David from the Red Shield organization. Upon returning to Okinawa, his investigation stalls when his newspaper supervisor refuses to fund a trip to France to continue his research. His path crosses with a spirited young woman named Mao Jahana, who is searching for her friend Kai. Realizing Okamura can help her find Kai, Mao forcefully partners with him, stealing money from her Yakuza father to finance their journey. Their partnership, which begins under unusual circumstances, becomes a central part of his story.

Despite initial friction and regular bickering, Okamura and Mao work effectively together. Okamura is generally cynical and often expresses annoyance at Mao's tempestuous and impulsive nature, but he never truly tires of her company. Their investigation leads them to Paris, where they reunite with Saya and her group. Although initially viewed as nuisances, Okamura's sharp investigative skills are eventually recognized by David, who requests his aid in looking into a concert being held by Diva, Saya's adversary. Following this, Okamura and Mao become unofficial members of Saya's group, assisting with research in Los Angeles and later in New York after their apartment is destroyed.

His role in the story is that of a grounded, human perspective amidst the supernatural conflict. As a reporter, his primary contribution is his ability to gather information, make connections, and document events through photography. His personal camera is a notable possession; on one occasion, when asked to accompany the others on a dangerous mission to Staten Island, he entrusts his favorite camera to Mao, asking her to look after it without offering an explanation. This act signifies a deep level of trust and hints at his unspoken feelings. Throughout the series, his cynical outlook is gradually tempered by his growing partnership with Mao and his commitment to uncovering the global conspiracy involving the Chiropterans. By the end of the series, Okamura decides to travel to the Middle East, and Mao chooses to join him.