Shinji Ogawa operates as an agent for S.O.N.G. while publicly managing Tsubasa Kazanari's idol career, meticulously balancing her public schedule with the secrecy of her Symphogear duties—a responsibility he previously upheld during her time in the duo Zwei Wing with Kanade Amou. His calm and quiet demeanor stems from childhood loss when his parents perished; his father once served under Genjuro Kazanari. This history cultivates profound trust toward Tsubasa and his comrades. He belongs to a globally scattered clan famed for versatile talents, alongside his older brother Souji Ogawa and younger brother Suteinu Ogawa.

Physically, Shinji sports brown hair and yellow eyes, typically clad in a black suit, white collared shirt, and black tie, adding glasses during managerial tasks. His ninja lineage grants elite combat prowess despite lacking a Symphogear, enabling superhuman speed, illusory movement, water-running, and pinpoint marksmanship. Key techniques include "Shadow Weaving"—disabling targets by curving bullets through their shadows—and "Ninja Art: Car Clone," generating illusory vehicle decoys to dodge assaults. He taught Shadow Weaving to Tsubasa.

Throughout operations, Shinji delivers unwavering tactical and emotional support. Early on, he escorts Hibiki Tachibana to Section Two, releasing her restraints per Tsubasa's order. He later consoles Hibiki about Tsubasa's guarded grief over Kanade's death, clarifying the Superb Song's risks. He intervenes critically during Noise attacks, retrieving Miku Kohinata's bag and rescuing her from ambushes. His insight into Tsubasa's sorrow proves vital when she nears self-sacrifice; he articulates her turmoil to Hibiki, mending their bond. He anticipates Tsubasa's actions, notably removing his glasses to signal impending reminders about her singer obligations.

His duties extend to practical aid in Tsubasa's daily life, such as cleaning her room—a habit she only found embarrassing after Hibiki noted its implications involving her underwear. This arrangement persists in later events. Subsequent missions further showcase his skills: he extracts Shirabe Tsukuyomi via bridal carry and deploys car-cloning to evade enemy fire. His driving executes extreme, mission-aligned high-speed maneuvers that leave passengers unscathed. The narrative progressively reveals his clan's expansive capabilities, underscoring their collective expertise.