Ryo Saeba

Ryo Saeba is one of the main characters in A.H. He appears as sweeper City Hunter and is introduced at the beginning of the story at having lost Kaori after an accident claimed her life.

Plot
Initially, Ryo believes that Kaori's heart continues to live elsewhere after her death despite not knowing to whom it's borne. After hearing from Umibozu about Kaori's 'return', he wanders the street of Shinjuku in search for her. He meets Glass Heart gradually in the course of the story and a bond unfolds between them.

Kaori Makimura
His beloved and partner of the City Hunter Team. They first met when he had suffered a gunshot wound and Kaori brought him to Doc's clinic. It was for Kaori that he swore to protect Hideyuki.

Hideyuki Makimura
Ryo got to know Hideyuki after Kaori brought him to Doc's clinic and later form the City Hunter partnership behind the scenes.

Umibozu
An old friend who owns Cat's Eye Cafe and goes way back with him.

Li Jian Qiang
The triad boss from Taiwan who hired him to rescue his twin brother.

Li Jian De
The twin brother of Li Jian Qiang whom Ryo got acquainted with after rescuing him.

Xiang Ying
AKA Glass Heart, the young girl who carries Kaori's transplanted heart. He eventually forms a paternal bond with her.

Saeko Nogami
The Shinjuku West Police Chief whom he has known for a long time.

Doc
An elderly doctor who owns a private clinic.