Shion Otosaka, initially known only as Gentleman, is a student at Shadowverse Battle College who begins attending classes remotely, avoiding physical interaction. Shion exclusively interacts through the eccentric, spontaneous, and occasionally arrogant digital avatar Lady & Gentleman. This persona masks Shion's severe social anxiety and fear of rejection, rooted in a belief of inherent unlikability; Shion characterizes it as a front for a "heartless, selfish jerk" who preemptively pushes people away.

Originally the hidden leader of the Sixth Magic club, Shion covertly directs members by issuing commands through an earphone to acting president Shinobu Miki. This controlling method leads to rejection by the club, prompting Shion's withdrawal into isolation. After losing a Shadowverse battle to Light Tenryu, Shion leaves Sixth Magic and joins Seventh Flame, though initially maintains distance by operating solely through the Gentleman avatar.

Ren Kazamatsuri and Tsubasa Takanashi discover Shion's true identity at an arcade. Following a Shadowverse loss to Tsubasa, Shion requests secrecy about their identity. While Tsubasa honors this request, the encounter marks Shion's first tentative steps toward connection. Representing Seventh Flame against Shinobu Miki in the Shadowverse Club Tournament, Shion fears Shinobu's resentment over past manipulation but wins the match with club support, promising genuine communication afterward.

A shift occurs during a resort trip to Genesis Island where Shion appears in person before clubmates and other presidents. This act bolsters confidence, leading Shion to attend club activities without the Gentleman avatar to support Light Tenryu's battle against Mikado Shirogane. However, during the Shadowverse World Ranking event, social anxiety resurfaces, hindering battle requests. After accumulating wins, Shion challenges Grand Master player Warden Craft. Defeat and Warden's critique of Shion's solitary existence triggers deep introspection.

Shion achieves fifth place in the World Ranking but remains emotionally distant during the conflict against the Seven Shadows. Confronting Warden again in the Shadow Area, Shion seeks answers about solitude versus companionship. Despite support from Ren and Tsubasa during the battle, internal conflict persists over fears that bonds inevitably break. Witnessing Ren's unwavering defense—asserting no one needs to change their core self—allows Shion to accept uncertainty in relationships. This realization leads to victory against Warden and strengthens bonds with Ren and Tsubasa.

Later, during the mission to halt the Shade invasion at Genesis Corporation, Shion expresses doubt about the mission's purpose but commits to assisting. When strategizing team divisions, Shion volunteers for the group aiding Shadoba College but is reassigned by Mikado to lead operations at Genesis headquarters. Shion disobeys this order to intercept Warden, who abandoned the mission for personal goals. Their Shadowverse battle includes sensory feedback through Shion's avatar, risking physical harm. During the duel, Shion condemns Warden's selfishness and affirms commitment to preserving bonds, triggering Milady's evolution into Mystic Empress and securing victory. Warden later reveals the lethal stakes were fabricated, acknowledging the battle changed his perspective.

Following the resolution of the Arc Ruler and Wolfram Zerga crises, Shion overcomes most social anxiety barriers. They begin attending Shadowverse Battle College in person regularly and interact directly with Seventh Flame members, retiring the Gentleman avatar entirely. Shion retains interests in rabbits, video games, and chess, and uses a Runecraft deck focused on chess-themed cards like Magical Pawns and Mystic King.