Asumi Kominami is a main heroine, daughter of Soujiro and Kasumi Kominami. An alumnus of Ichinose Academy, she graduated one year prior to Nariyuki Yuiga and the other heroines. After high school, she became a rōnin specifically to gain admission to a top national medical university, pursuing her childhood dream of succeeding her father in his family-run clinic facing competition from larger hospitals.

Petite in stature with lilac hair tied in twin pigtails and gray eyes, Asumi is frequently mistaken for a middle school student, a misconception she dislikes. She works part-time at the maid café "High Stage" under the persona "Fairy Maid A-shi-yu-mi-i," wearing a maid uniform there, and favors dresses or long skirts casually.

Her personality blends playful teasing with underlying determination. She enjoys lightheartedly teasing Nariyuki Yuiga, often placing him in mildly embarrassing situations. This dynamic intensifies when she enlists him to pretend to be her boyfriend to deceive her father. Despite the fabricated relationship, her teasing occasionally hints at deeper, ambiguous feelings, such as questioning him about her "real feelings" or kissing his cheek during study. She strongly resists being called a "repeater" or defined solely by her academic struggles.

Academically, Asumi excels in humanities but struggles critically in science subjects like chemistry and biology, essential for medical entrance exams. She works at the café to finance cram school tuition and exam fees. Her resolve to become a doctor strengthens upon learning of her family clinic's financial difficulties, driving her persistent efforts to overcome her weaknesses, often aided by Nariyuki’s science tutoring.

Initially neutral toward Nariyuki, Asumi grows closer after he discovers her secret job. Their fabricated relationship evolves into genuine camaraderie, with Asumi offering him life advice and emotional support, adopting an older-sister-like role. She maintains cordial but academically contentious interactions with Mafuyu Kirisu, who initially discouraged her medical ambitions. She also interacts with Rizu Ogata, Fumino Furuhashi, and Uruka Takemoto during summer cram sessions.

Her character arc culminates in dedicated medical pursuit. Completing her residency on a remote island where Nariyuki coincidentally teaches, she performs emergency surgery on him after he sustains life-threatening injuries saving students during a storm. This act solidifies her feelings, leading to his recovery, his proposal, their marriage, and plans for a family, fulfilling her dual aspirations.

Additional traits include a fear of glires (rodents) and skill in playing the electric guitar. Her name "Asumi" combines "tomorrow" (asu) and "fruit" (mi), while "Kominami" means "small," "beautiful," and "wave."