Before “Decoy” became Shohei Ohtani’s famous companion, the Ohtani family had a Golden Retriever named Ace.
Ace joined the family when Ohtani was in first grade and lived with them for about sixteen years.

Although a large dog, Ace was kept indoors and treated as a true member of the family—sometimes even sitting on the sofa to watch TV with them. Ohtani recalls that, as the youngest child, he was often seen as “lower ranking” by Ace.

One childhood incident became a family story. While preparing for a trip to Tokyo Disneyland, Ace grabbed Ohtani’s socks, and when Ohtani tried to take them back, the dog bit his right arm. The injury was not serious, but Ohtani’s mother later joked that if it had been worse, “there would be no pitcher Shohei.”

A faint scar from that bite remains on Ohtani’s arm, but he remembers it with affection.
“For all that,” he says, “Ace was adorable.”
After Ace passed away, the next dog to enter Ohtani’s life was Decoy.

Source

This quote comes from a Japanese book published in Japan and is not currently available in English.

Opening a Path, Crossing the Ocean: The True Story of Shohei Ohtani, p.62