Luke is a young boy living in Estelle's hometown of Rolent.
He lives in the residence in the north-western section of the city together with his parents, but can often be found playing on the streets together with his friends.
Luke's attitude towards Estelle is an extremely abrasive one and after an argument between the two, Estelle wonders out loud if Luke dislikes her. Joshua suggests the opposite may actually be true and Luke may be harboring a slight crush on her which he tries to cover up by picking fights with her.
When Pat hears talk about the Esmelas Tower to the north of Rolent, he makes the mistake of telling Luke about it, who promptly decides to go there and see the place for himself and allows Pat to come with him. The boys end up getting more than they bargained for when they're assaulted by several monsters inside the tower. Fortunately for them, Estelle and Joshua come to their rescue and defeat the winged felines that were about to attack the boys.
Luke is genuinely impressed by Estelle's combat prowess, but Estelle is in no mood for compliments as she roughly grabs him and is about to give him a spanking to punish him for endangering himself and Pat when another monster manages to sneak up on the two and is about to attack Estelle. Before it can do so, however, Cassius drops in and takes out the monster in a single hit. Immediately noticing the difference in experience, Luke promptly drops his admiration for Estelle and praises Cassius to high heaven instead, who all too happy to let him, much to Estelle's chagrin.
Luke gets a stern talking-to when he gets back home. When Estelle talks to him later, he admits she was still pretty cool in his eyes and genuinely thanks her for saving him.
Beneath the surface, Luke is a lot like Estelle: energetic, considered troublesome at Sunday school, quick to drag his friend along in whatever he has in mind and extremely passionate about his dream of becoming a bracer. (if his diary is to be believed)