Yūki Shibayama is a first-year Nekoma High student and the volleyball team's libero, notable as the squad's shortest player at 162.5 cm and 53.3 kg. He sports jet-black center-parted hair, thick eyebrows, and dark eyes, transitioning to a shorter style post-high school. During matches, he dons the libero's white jersey and red shorts. Initially shy and easily rattled, Shibayama possesses underlying determination and a strong work ethic. His journey involves overcoming self-doubt about his skills compared to teammates, gradually building confidence and sociability. His drive stems from proving his worth despite lacking natural talent. Key moments include replacing injured libero Morisuke Yaku against Nohebi Academy. Targeted for inexperience, he faltered initially but rallied upon recalling Yaku's words about Nekoma's libero legacy. His critical reception of Suguru Daishō's serve tied the set, and his strategic coverage of Lev Haiba secured the match-winning point—solidifying his team belonging. At Tokyo Nationals, he offered tactical insights (like advocating overhand passes against float serves) and attempted to advise Lev, though confusingly phrased. He participated in Nekoma's historic clash against Karasuno, shaking hands post-match with Asahi Azumane. His high school stats: Power 1/5, Jumping 3/5 (280 cm reach), Stamina 2/5, Game Sense 3/5, Technique 2/5, Speed 4/5. Post-timeskip, specialized skills improved: Serve Reception 9/10, Dig 9/10, Setting 6/10. Relationships feature frequent pairing with fellow first-year Sō Inuoka during matches. He comforts and guides Lev Haiba toward teamwork, fostering effective collaboration. While respecting Yaku, he feels intimidated replacing him. Interactions with seniors include misreading Asahi Azumane's helpful intent as displeasure. Post-graduation, Shibayama plays professionally as libero for Tōkai Heavy Industries Esperanza (Division 2). He favors omurice, is a Sagittarius, and voices recurring concerns about receiving skills compared to teammates—resolving to train harder. As Nekoma’s youngest first-year, his persistence defines his path.