Adam Hamasaki is a medical volunteer who joined the Arkham City medical team lead by Aaron Cash. He was working inside the Gotham Cathedral when some thugs allied with Harley Quinn and Joker broke in.
After Batman saves the medical personnel, he talks to Adam and he told him about the condition of a doctor. He was later captured by Riddler and was the first doctor saved by Batman. He then told Batman one of the many codes to Riddler's messages and was later able to make his way back to the church. He was eventually joined by Eddie Burlow, Jack Ryder, Vicki Vale, and Quincy Sharp.