Hiro Noshimuri was a corrupt business man with heavy ties to the Yakuza that appeared in Ke Kinohi (episode). Hiro is also responsible for the unintended death of Lieutenant Commander Steve McGarrett (2010)'s mother and the kidnapping of Mary Ann McGarrett, Steve's sister along with his brother, Kouji Noshimuri.
Biography
Pre-Series
In 1992, Hiro, a crime boss was being hunted by Honolulu Police Department Detective John McGarrett who sought to arrest Hiro for his involvement in crime.
The Yakuza, however wanted to keep Hiro undercover and as such, Kouji, Hido's brother placed a bomb underneath John's car although his wife, Doris was the one who drove it, resulting in her death although it was later revealed that Doris who was also a CIA agent had faked her death in the explosion.
Hawaii Five-0 Season 1
With Doris in hiding and John now dead, their son, Lieutenant Commander Steve McGarrett (2010), now the leader of the Hawaii Five-0 Task Force took on the role of tracking down and arresting Hiro which Steve did.
As such, Hiro was also imprisoned.
Hawaii Five-0 Season 2
After being released from prison, Joe White, Steve's mentor kidnapped Hiro so that Joe could see what information Hiro had in regards to "Shelburne".
In Pahele (episode), Joe captured Hiro again and the two agreed to work together so that Hiro's son, Adam Noshimuri would not become a target of Wo Fat's.
Hiro later fled to Japan for a small amount of time but Wo Fat eventually tracked Hiro down and killed him with Wo Fat sending various body parts back to Adam who revealed this to his girlfriend, Officer Kono Kalakaua (2010).