Yuzu, a male Hybrid Child, is an android whose development hinges on the love and care bestowed by his owner. Crafted by Kuroda for Seya—a swordsman burdened by wartime guilt—Yuzu’s physical and emotional evolution depends on Seya’s willingness to embrace vulnerability. Initially, Yuzu’s growth stalls, his childlike form a mirror to Seya’s unresolved guilt and emotional barriers, which stifle their bond. Yuzu sports short orange hair and light blue eyes, with subtly artificial coloring in both features distinguishing him from human counterparts. Frustrated by his static appearance, he seeks advice to hasten maturation. A comedic miscommunication occurs when another Hybrid Child jests about physical intimacy as a solution, prompting Seya to gently redirect him toward the necessity of emotional intimacy instead. As Seya confronts his trauma, sharing regrets and sorrow, Yuzu’s form matures in tandem with their deepening connection. Their journey peaks with Yuzu’s adult form embodying Seya’s newfound capacity for love and healing, concluding their arc with hopeful resolution amid the series’ darker narratives. Yuzu balances wide-eyed curiosity with perceptive emotional depth, driven by an earnest desire to support Seya. His fondness for castella sponge cake surfaces as a comforting motif. Through unwavering devotion, Yuzu becomes the catalyst for Seya’s redemption, underscoring the narrative’s exploration of artificial beings nurturing human resilience through compassion.