Jiro has dark brown hair, brown eyes, and he wears a white suit with a blue tie and white pants. He also wears black glasses and white hat. He also has a happy and good natured personality towards Naoko and loves her very much. Jiro is also trustworthy and hardworking when it comes to his love for airplanes.
At the beginning of the film, Jiro first appears getting on top of his roof and flying in an airplane over Japan, but, his dream is dashed however, when he finds that nearsighted people cannot fly airplanes. Then, he meets Caproni, an Italian airplane designer who tells him that even though he cannot fly planes, he can still create them.
Then, Jiro begins to study all about planes, airplane design and Caproni himself, who appears frequently in his dreams. Later, after years have passed, Jiro is making his way to the University of Japan when the Great Kanto Earthquake of 1923 hits. Before, however, Jiro meets Naoko as his hat flies away on the breeze and Naoko almost falls off the platform of the train trying to catch it.
Now, the earthquake has ended and left Naoko and her maid in despair because Naoko has broken her leg. But, Jiro however, returns Naoko's maid to the safety of their home without giving his name and rushes off to the university. Pretty soon, Jiro studies at the university and then graduates to work at an airplane design firm. Then, after a few failed attempts of trying to create the perfect airplane fighter, Jiro goes on a vacation to a summer resort where he unknowingly runs into Naoko again.
Both of them, however, are too shy to meet again. One day, Jiro takes a walk by a river, and runs into Naoko again after seeing him catch her umbrella. Naoko explains that she always felt like they would meet again because the wind had brought them together. They begin to fall in love and begin a happy and good natured and loving relationship. Naoko, however, is afflicted with tuberculosis and refuses to marry Jiro until she recovers.
After some months of going back to his work, Jiro continues to work on the chief design of his first successful aircraft in the home of his manager. Naoko, meanwhile, has been recuperating in an airplane sanatorium, but, cannot bare being apart from Jiro. They quickly get married through an impromptu wedding. However, they lend support to one another as Naoko's health begins to decline. On the day of the test flight, Naoko feels well enough to take a walk, which results in her leaving Jiro and her family and friends behind.
Jiro finally notices that on the day of the test flight, he feels a burst of wind and realizes that Naoko has died. In the final scene, Jiro is reunited with Naoko and Caproni with Naoko telling Jiro that he has to live with the trust and faith and love that she has in him.
Jiro Horikoshi is very similar to Tatsuo Kusakabe
Jiro Horikoshi makes a cameo appearance in My Neighbor Totoro