Helio is a Balloon Dragon who lives in a fortress with his best friend, a human girl named Anigi. Every other day, Helio goes on an adventure. He returns to the castle at the end of the day. He shares any treasure he finds with Anigi and tells her about his adventures.
One day, Helio gets lost while exploring the Sky Islands for the first time. He finds himself surrounded by a group of monsters known as Grouches. They get enraged and chase after him for some reason. A few of them catch up to him and hurt him, but he barely manages to escape into an abandoned house. Helio takes a nap in this house for a bit too long. He wakes up and realizes how long the nap took and that he must be running late at this point, so he starts heading home.
Meanwhile, a thief known as El Ladron spots Helio away from the fortress, so he decides to take the chance to rob it. El Ladron has never succeeded in this before; will this be his lucky break?
