Yūki Shibayama, a first-year Nekoma High student, occupies the role of secondary libero under Morisuke Yaku. Standing at 162.5 cm with jet-black middle-parted hair and thick eyebrows, he remains the team’s shortest member, clad in a white libero jersey and red shorts during matches. Post-timeskip, his hair shortens, reflecting a matured appearance. Shy and prone to self-doubt, Shibayama grapples with insecurities when measured against Yaku’s defensive prowess, often questioning his own contributions. Yet he channels this uncertainty into rigorous practice, determined to carve his place. His resolve is tested during the Spring High Preliminary Arc when replacing the injured Yaku against Nohebi Academy. Branded a liability by opponents, he wavers initially before rallying with Yaku’s words about Nekoma’s libero legacy. A critical reception against Suguru Daishō’s serve at set point pivots the match, cementing his growth. Supportive bonds define his team dynamic. He partners with Sō Inuoka for mutual motivation and evolves a collaborative rapport with Lev Haiba, transitioning from post-loss consolations to strategizing jump float receptions. His analytical edge surfaces when dissecting Kuroo Tetsurō’s blocks to redirect spikes, showcasing tactical awareness. Post-graduation, he joins Tōkai Heavy Industries Esperanza as a Division 2 libero. Skill assessments highlight speed (4/5) and game sense (3/5) in high school, with power (1/5) and technique (2/5) lagging. Post-timeskip improvements elevate his dig and serve reception to 9/10, honing his defensive specialty. His declaration to validate his worth through action underscores a quiet tenacity. Personal trivia notes a preference for omurice and a Sagittarius birthdate of December 16.