Shinnosuke and his Grandfather both live in the forests of Ryugenzawa. Here they protect the local villagers from the giant animals that they once kept as pets. Many years ago, Shinnosuke's Grandfather was in charge of a small petting zoo in Ryugenzawa, and when the animals escaped they grew to monsterous sizes due to the Water of Life found in the forest.
Akane met Shinnosuke when she was a child and got lost while vacationing in Ryugenzawa. Shinnosuke saved her from a giant platypus, but he was severely injured in the process.
Shinnosuke now depends on the Water of Life to cure the deep gashes that plague his life. Without frequent exposure to the Water of Life Shinnosuke will die. Because Akane feels responsible for his condition she chooses to stay with him and try her best to help him as he had done for her. This places a major strain on her relationship with Ranma.
One of Shinnosuke's major flaws is that he has no short-term or long-term memory. He often forgets names and people altogether. In fact one of the few things he is able to remember on a regular basis is Akane's name, which is a testament to his deep feelings for her.
The Meaning Behind the Name
Shinnosuke has some very interesting ways of translating his name. "Shi" means "death" which refers to the fact that he is near death, but "shin" means "devotion or deep affection," which he obviously has for Akane. The "suke" part of his name can mean "assistance".
Takeshi Kusao & Jason Gray-Stanford
Takeshi Kusao is the famous voice of Shinnosuke, and is probably best know for his role as Trunks on Dragon Ball Z as well as Youta Moeteuchi in Video Girl Ai and Kyouichi Saionji on Revolutionary Girl Utena. He shares a credit with his English counterpart as they both played the title role in Ogre Slayer.
Jason Gray-Stanford as mentioned previously was the Ogre Slayer, but he is best known as Yusaku Godai in Maison Ikkoku. His other works include Yuta in Mermaid's Scar, Haruhiko Kazama in Please Save My Earth and Joe Higashi in Fatal Fury.