Tao Gwen is a 29-year-old male standing 196 centimeters tall, with dark green hair reaching his chest and black eyes. He once worked as a waiter at the Goldfish Teahouse, where he befriended regular customer Hajime Kudou. During this time, Tao informed Reiko Kujirai about her past identity and engagement to Hajime, shortly before vanishing.

After his disappearance, Tao resurfaced and discerned that the present Reiko differed from the "Kujirai B" he previously knew. His past includes a significant romantic involvement with Miyuki Hebinuma, president of Hebinuma Pharmaceutical, partnering with her to investigate Kowloon's mysteries. Miyuki abruptly severed their relationship; in response, Tao bit her mouth, leaving a lasting scar intended as a reminder of their connection.

Following the split from Miyuki, Tao allied with Reiko Kujirai and Yaomay, aiding their quest to uncover Kowloon's secrets. He applied his investigative background and knowledge of the city to their efforts. Lingering emotional ties to his past surface when he describes Miyuki to Yaomay as a "jasmine-scented individual."

Tao appears to have another version of himself within the story's framework. His path shifted from service work to active participation in unraveling the city's enigmas, maintaining consistent involvement in the core mysteries surrounding Kowloon and its inhabitants.