Saejima presents as a relatively tall young man with short black hair and dark brown eyes, usually wearing a small smile or neutral expression. He occasionally displays flustered reactions, particularly during interactions with Komori. His standard work attire features casual business clothing, often without a suit jacket and favoring plain styles in basic colors. Outside work, he opts for everyday wear like t-shirts, jackets, and sweaters. Personality-wise, Saejima exhibits a laid-back, calm, and easygoing demeanor compared to colleagues. He demonstrates introverted tendencies, speaking less and remaining reserved in group settings. He enjoys outdoor activities including camping and hiking. His feelings for Komori prompt straightforward romantic gestures like gifts and compliments, though he frequently retracts them last moment due to embarrassment. When flustered, he often redirects compliments toward foxes instead of Komori directly, alluding to her fox spirit heritage. Saejima and Komori knew each other before meeting colleagues Himuro and Fuyutsuki, though their relationship deepened over time. Saejima developed romantic feelings first, initiating shy gestures Komori initially missed due to her airheaded nature. During a group vacation, he privately confessed to her at a bathhouse. They later announced their coupled status to Himuro and Fuyutsuki, who responded with nonchalant applause, suggesting anticipated acceptance. A Christmas visual reinforced their relationship, depicting them together in Santa costumes surrounded by presents. His friendship with Himuro involves comfortable coexistence; Saejima adapted early to Himuro’s involuntary office blizzards and casually notifies him when weather effects occur, indicating mutual ease. They frequently engage in casual conversations and spend time together in and outside work. With Fuyutsuki, Saejima maintains a friendly connection through group activities but shares fewer direct one-on-one interactions.