Adam Noshimuri is the son of Hiro Noshimuri, former leader of the Japanese Yakuza. He is seen leaving court with his father after the trial of the kidnapping of McGarrett's sister. Joe White threatens both with a gun and kidnaps Hiro in order to help him fake his own death.
Adam attempts to find the truth about his father and twice threatens McGarrett and Joe White. Adam successfully tracks down Joe and beats him for information. McGarrett rescues Joe and the two leave.
After finding out the truth about his father's faked death, he agrees to ally himself with McGarrett to take down Wo Fat.
In Ua Hopu (episode), he is revealed to be Officer Kono Kalakaua's love interest. In this episode Wo Fat has killed his father and sent Adam body parts.
In retaliation, Adam attempts to have him killed.
At the end of Powehiwehi (episode), Kono tells Adam she wants to be his wife.
Season 3
It is unknown how he managed to get out of jail after being arrested along with the rest of the Yakuza. In La O Na Makuahine (episode), while Chin was going to save his wife, he called Adam and explained Kono was going to be dumped into the ocean and he needed Adam to save her.
He arrived just as Kono was starting to drown and managed to perform CPR and save her just as Malia died. He managed to explain everything to Kono.
At the end of the episode, he waited on Kono's front door step as she got back from work, they talked about what happened, and she thanked him for saving her. He claimed he still owed her, saying that she saved him twice, the first time being when they first met, and the second time when Wo Fat returned to Hawaii after being captured by Lieutenant Commander Steve McGarrett (2010), and he was almost killed by his own men.
His brother, Michael, has been released from prison, and appears to be willing to help make the family business legitimate. He has even gone to such lengths as keeping secrets from Kono about cutting his families ties with the Yakuza by travelling to Japan to meet with "Sato" the current head of the Yakuza.
In the finale, he's ordered by the Five-0 Task to leave for Shanghai with Kono and Doris McGarrett to be in hidden custody from his brother's associates within the Japaneses Yakuza who want Adam dead for killing his brother.
Season 4
He and Kono return to Hawaii after the Yakuza was taken down.
Season 5
In Powehiwehi (episode), a year after Adam and Kono safely return to Hawaii, Adam tells Kono he thought they would already be married. Kono initially resists because she still isn't comfortable with the corrupt past of Adam's family business and asks him to sell it so they can have a fresh start. By the end of the episode, Adam is seen making plans to sell the company and Kono tells him that she wants to be his wife no matter what.