Tomoki Sakurai, a teenage boy in Sorami City, initially seeks an uneventful life guided by his motto of peace and quiet. His childhood featured recurring dreams of the angelic Daedalus, awakening him in tears and hinting at a connection to Synapse's celestial realm. At ten, his parents departed, leaving him with his grandfather, whose influence shaped Tomoki's lecherous tendencies and eccentric worldview. A pivotal childhood incident—leading friends to a bird's nest that caused injuries—isolated him socially until Sohara Mitsuki moved nearby. They bonded over shared loneliness, becoming inseparable as Tomoki taught her karate and orange cultivation. His personality presents a dichotomy: extreme perversion manifests through voyeurism, harassment, and transforming into "Tomoko" to infiltrate female spaces, yet he simultaneously exhibits profound compassion and protectiveness. This duality emerges clearly with Synapse's mechanical Angeloids, as he rejects their servitude programming to champion their autonomy, emotions, and freedom. Leadership surfaces during conflicts, like orchestrating snowball battle strategies against formidable foes such as Sohara. Unusual physical traits include imperviousness to genital trauma and emitting lightning from his groin, dubbed "Thunder Wang" or "Dong of Thunder." Romantic feelings develop for Sohara, Nymph, Astraea, and Hiyori Kazane, but his behavior toward Ikaros diverges—refraining from perverse acts and displaying unconscious reverence Sohara calls "extremely strong feelings." This creates a central "love pentagon," with Tomoki initially oblivious to Angeloid affections. His bond with Ikaros forms an emotional core: he prioritizes her well-being, teaches human experiences, and reacts intensely to her suffering. A manga moment reveals him confessing deep affection for her during a tournament, comically undermined by declaring equal love for a mannequin prize. Character development intensifies in "Eternal My Master" when Tomoki misinterprets Ikaros's emotional stagnation as stemming from their bond and severs their master-servant chain. This backfires, causing her profound distress. After recognizing her fear of abandonment and hearing her desperate plea to remain his master, he reinstates their bond, acknowledging her desire for eternal companionship. Their journey to Synapse culminates in Ikaros sacrificing herself while confessing love, shattering Tomoki until her resurrection via his final wish. He later vows permanence beside her. Tomoki cherishes Angeloids and friends as family despite lamenting disruptions to his tranquility. He demonstrates exceptional loyalty, risking his life—intervening during Chaos's breakdown or confronting Synapse's ruler—and retains memories of erased individuals like Hiyori when others forget. The spin-off "Yuuryō Bukken Mō Dame Sō" depicts him at twenty-six: unemployed, interacting online as "T.S.," and financially supporting Yurara Tategami's cosplay hobby by gifting outfits like bunny suits and police uniforms, reflecting enduring eccentric interests.