Hiro is wise, very dignified, and enormously kind. He is friendly and is able to find good in any engine he meets. He does not appear to hold a grudge; in his first appearance, he helped Spencer after an accident, despite Spencer previously trying to send Hiro to the smelter's yard.
Hiro once lived on a faraway island. He was the strongest engine on his railway, and was famously known as the "Master of the Railway". He was eventually brought to Sodor where he worked for many years. However, he began to show his age, and the works did not have the necessary parts to repair him. To escape being scrapped, he was put on a siding, where he had to wait for the parts to come from his homeland. However, the parts never came and Hiro was all but forgotten.
Thomas eventually found him and, fearing Hiro would be scrapped if he was not Really Useful, promised to bring him back to his former glory while keeping him a secret from Sir Topham Hatt. Thomas also had many of his friends help in the restoration, and Hiro quickly gained their friendship. After breaking down again while trying to avoid Spencer, Hiro was hidden away in another siding, where passing engines visited him and kept him company.
When Sir Topham Hatt found out about the situation, Hiro was brought to the Sodor Steamworks, where Victor oversaw his restoration. Once Hiro was restored, he helped Spencer after his accident, and worked with him and Thomas to finish the Duke and Duchess's summer house. Despite everything, Hiro had grown homesick, so Sir Topham Hatt arranged for him to be sent back to his homeland.
Hiro eventually came back to Sodor to help the engines with the summer holiday traffic. Upon his arrival, Hiro went to the Steamworks to be examined and then went to Knapford station for his welcome party, which was almost delayed as Thomas was trying to find a welcome present for Hiro instead of telling the other engines about the party. But, Hiro told Thomas that having his friends at the party was the best welcome present. During his visit, Hiro told Thomas to take the load of bees through the woods, which Thomas ignored. However, Thomas took Hiro's advice after taking Hiro's flower truck to get the bees back to their hives. Later on, Hiro saw the Fat Controller, and assumed he was too busy to give orders to his engines. So, he tried to help the Fat Controller by giving out the orders - but he only succeeded in becoming "Master of the Muddle". However, he made up for his mistakes by telling the engines to go to Knapford and await orders from the Fat Controller.
Hiro is still on loan to the Fat Controller. He saw Jobi Wood being delivered to the Docks and told Thomas about where it came from. He later pushed Henry to the Steamworks to have his side-rods repaired. And when Hiro became homesick, Thomas took him to Misty Island, which reminded Hiro of his home.
Later, Hiro, along with Henry, took on some bad coal. While Henry did not want to carry on, Hiro was determined to get the job done. He did so, but during his next job of transporting girders with Henry, Hiro broke down and Henry had to come to the rescue.
Once, Diesel tried to teach him how to handle trucks, suggesting that the only way of tackling them was with force. However, Hiro insisted that being gentle was the best policy. However, when Diesel stuck to his own belief, he ended up causing Hiro's milk churns to spill over the Fat Controller — twice! After this, Diesel was found out, and Hiro was tasked with teaching Diesel the correct way to treat trucks!
In the eighteenth season, he stopped Caitlin while he was on the mainland after she accidently took Annie and Clarabel, and brought them back to Thomas on Sodor. Later, he helped clear the tracks so Connor could deliver the last of his passengers on Christmas Eve, and nearly mistook Harold for Santa Claus.
Hiro is an old steam engine who has been on Sodor for a very long time and was originally known as the "Master of the Railway." He is grand, masterful, and mature. He has an appreciation for serenity and order and often thinks fondly of his homeland, far away, where he was once one of the strongest engines. Hiro fell victim to neglect when waiting upon parts to arrive for him from his island, when he began to break down and became lost. He was eventually rediscovered by Thomas, who, despite some problems in worrying about sharing the discovery of Hiro with the Fat Controller, helped Hiro be fully restored to his former glory. Hiro continues to be gentle, wise, and graceful, as well as a useful engine on the railway and good friend to the other engines, especially Thomas.
Main Weaponary in Stuington's Series
- Japanese Type 99 Light Machine Gun
- 2 Daishō swords
- Japanese Naginata
- Shuriken Ninja stars
- Hook Swords
- Phaser cannon
Relationship with Princess Luna
Hiro also has a relationship with Princess Luna. It all began when
- Hiro met Pooh, Twilight and their friends in in Pooh's Adventures of Thomas & Friends: Hero of the Rails and Tigger refers to him as "Hiro-boy" starting in Pooh's Adventures of Thomas & Friends: The Biggest Present of All.
- Hiro will meet Ash Ketchum, Littlefoot, SpongeBob, Simba, Tai and their friends in Ash's Adventures of Thomas & Friends: Hero of the Rails.
- Hiro is also the Galaxy Express 999's friend.
- Hiro and Fluttershy are best friends.
- Hiro is one of the two mentors of the Cutie Mark Crusaders (the second mentor is Stephen).
- Hiro is also Princess Luna's boyfriend and then marries her in The Night to Remember.
- Hiro will meet Ryan, Crash and their friends in Ryan and Crash's Adventures of Thomas and Friends: Hero of the Rails.