Hotaru Nowaki operates as a receptionist for B.A.B.E.L., leveraging her Level 5 telepathy and clairvoyance within the esper duo Double Face alongside partner Natsuko Tokiwa. Stationed at the organization’s headquarters, she screens visitors by psychically detecting concealed threats—such as unmasking disguised individuals through hidden physical traits or unspoken motives—to ensure security protocols.

Her name originates from *The Tale of Genji*: "Nowaki" combines the characters for "field" and "minute," while "Hotaru" references a chapter title. This mirrors the series’ thematic ties to the literary classic, with her surname further nodding to a historical link involving Hikaru Genji’s half-brother.

Beyond routine screenings, Hotaru’s role expands into investigative assignments when required. Her telepathy scans thoughts and emotions, while clairvoyance provides real-time surveillance, exemplified when she exposed a visitor’s wig and probed his false identity. She maintains a no-nonsense professionalism during interactions, coordinating with Natsuko to align vigilance with institutional procedures. Though her personal background remains undocumented in accessible records, her steady presence within B.A.B.E.L.’s framework underscores her role as a dependable asset to Double Face and the organization’s operations.