OVA
Description
Oscar is a young human boy who enters Marielle's life around the time she begins attending a boarding school after her health improves. Among the human characters, he stands out for his intense fascination with aliens and outer space, an interest that drives much of his involvement in the story. When he finds the pointed hat that belongs to Memoru, the tiny alien girl who has become Marielle's friend, he immediately senses that it is not an ordinary object and becomes convinced it must belong to an alien. This belief inspires him to start searching for the alien he assumes is nearby, and his determined curiosity puts Marielle in the position of trying to keep her small friends hidden while also working to recover the lost hat.

In terms of personality, Oscar is enthusiastic, curious, and friendly, with a somewhat single-minded passion for the unknown. His warmth allows him to form a genuine friendship with Marielle, and their connection carries a gentle romantic undertone. However, his personal life is complicated by the existence of his fiancée, Grace, who becomes jealous of the attention Oscar gives to Marielle. Grace's resentment leads to Marielle being bullied at school, which creates strain in Oscar's relationships and forces him to balance his affection for Marielle against his existing commitment to Grace.

Oscar's role in the narrative is primarily that of a friend and potential romantic interest for Marielle. He provides her with one of her few close human connections and introduces a source of conflict through Grace's jealousy. His encounter with the pointed hat marks the beginning of his awareness of the aliens, and he eventually befriends them as well, with his bond to Marielle serving as the bridge between the human world and the world of Memoru and her people.

Over the course of the story, Oscar's development centers on the choices he makes between the people who care about him. By the end, he ultimately chooses Grace, his fiancée, and his relationship with Marielle resolves into one of close friendship rather than romance. This decision reflects a sense of responsibility toward the commitment he already made and brings a quiet end to the romantic tension between him and Marielle.

Oscar does not possess any special powers or extraordinary talents. His notable trait is his keen, observant nature and his vivid imagination, which allow him to recognize the pointed hat as evidence of alien presence and to pursue the mystery with genuine curiosity. These qualities distinguish him from the other human characters and make him an important link between Marielle's ordinary life and the extraordinary presence of the aliens.