Kasim is a male student at Rosewood Academy, the central setting of Classroom for Heroes. He is a teenager with brown eyes and neck-length brown hair, and his typical attire includes gloves and boots. Kasim belongs to the school's lower-grade class and is a friend of the protagonist, Blade.

In terms of personality, Kasim is characterized as being lecherous, frivolous, and an easygoing individual who often acts on his impulses. He is known for his perverted tendencies, which are a frequent source of comedic relief within the story. Despite his generally unserious nature, he is a capable fighter who specializes in attacks using knives. His primary motivation is to be promoted from the lower class to the upper class of the academy.

Kasim's key relationships reveal different facets of his character. He harbors romantic feelings for a female student named Claire, frequently staring at her black hair, but he lacks the courage to confess his feelings to her. Claire is also aware of his lecherous behavior and is often wary of him, keeping a close watch to ensure his antics do not go too far. He is also identified as a close friend of Blade, the former hero, and is part of his social circle.

Kasim experiences notable character development later in the story. A major narrative arc introduces a new student, a genius necromancer named Lucia, who inexplicably targets Kasim for seduction, agreeing to all his lewd requests. This strange situation perplexes the other characters and drives a storyline that forces Claire to question her own feelings regarding her relationship with Kasim. During this arc, Kasim comes to inherit the legacy of a king and learns to wield the Imperial Emblem, a significant power, with Lucia's assistance. While this development serves to complete the abilities of the hero group and deepens his character in an interesting way, he largely remains an idiotic and perverted individual for the majority of the story.