|This article is about 'the book'. You may be looking for 'the episode, the Chinese DVD or the Malaysian DVD'.|
- “Hiro! What has four legs but never walks?"
"I don't know, Charlie."
- ―Charlie telling Hiro a joke
Happy Hiro is a Thomas Story Time book.
One morning, Thomas meets Hiro and Percy at Knapford station and toots them a greeting. Only Percy says "good morning" back. Thomas tells Hiro that he seems a little sad. Hiro admits that he is and rolls away.
Later on, Thomas meets Charlie at the docks. Thomas tells him that Hiro is feeling sad and asks Charlie to tell Hiro a joke. Charlie does so, but Hiro does not smile and puffs away. Thomas asks Hiro why he is feeling sad. Hiro tells Thomas that he misses his home and explains that he is an older engine who just wants to puff along quietly like he did back at home. Thomas does not listen to Hiro and thinks he knows just how to cheer him up.
Thomas takes Hiro to the Hollow Tree Tunnel and Hiro smiles when he hears the birds singing. Thomas does not listen to the birds and insists that they both chuff through the Hollow Tree Tunnel. Hiro is tired and tells Thomas that he just wants to puff quietly, but Thomas has another idea.
Hiro smiles when he sees the sea, but Thomas does not look at the sea. Thomas wants Hiro to puff quickly along the bumpy track with him. Hiro tells Thomas again that he just wants to puff quietly, but again Thomas does not listen to the old engine. At the Logging Station, Hiro spots some Jobi logs and asks Thomas if there are any Jobi tress they can visit. Thomas is not listening, until Hiro blurts out that he wants it all to stop. Thomas is sorry and tells Hiro that he thought he could make him happy, but has only made him unhappy. Thomas toots softly as he realises where he had gone wrong and admits that he should have listened to Hiro all along. He then invites Hiro to puff along quietly with him. Hiro happily accepts Thomas' invitation.
First, Thomas takes Hiro to look at the sea. Then Thomas takes Hiro back to the Hollow Tree Tunnel. This time, Hiro smiles as some birds settle on him. Finally, Thomas takes Hiro to where the Jobi trees grow. Hiro gasps when he sees the magnificent trees and gives the biggest smile of all. Hiro thanks Thomas for his special day and the two friends puff slowly and happily back to the engine sheds.
- This book is based on the fifteenth season episode, Happy Hiro.
- This book is featured on the Read & Play App, narrated by Mark Moraghan.
- After the Hollow Tree Tunnel, Thomas is said to take Hiro to Misty Island, but the Hollow Tree Tunnel is on Misty Island.