The “this” was a ring. The very ring now on Sato’s finger.
“Do you know why I became a police officer?” Detective Conan Episode 487
Takagi, red-faced and stammering, doesn’t say a word. Instead, he takes the ring from her palm, examines it briefly, and then—with more courage than he’s ever shown—slides it onto his own pinky finger. The “this” was a ring
Chiba, half-joking, asks if the groom is a "handsome elite from headquarters." Takagi, pale and sweating, can’t bring himself to ask her directly. Even Megure notices Takagi’s distress but offers only a cryptic, “Love isn’t always straightforward.” Before the personal drama can escalate, the squad is called to a murder scene in the Edogawa ward. A 34-year-old bank employee, Kiyoshi Inoue, has been found dead in his apartment, strangled with a necktie. The victim’s left ring finger has a pale indentation where a ring was recently removed. Instead, he takes the ring from her palm,
As the suspect is led away, Sato finally removes the ring and holds it out to Takagi.
Sato laughs—a real, unguarded laugh—and punches him lightly on the shoulder. Chiba, watching from behind a corner, gives a thumbs-up. That evening, Conan reports to Haibara over dinner at the Agasa residence. He concludes that Sato never intended to marry anyone else. The “wedding dress fitting” was actually a fitting for a bridesmaid’s dress for a friend’s wedding. The rumors were just gossip.
“I take it off when I find the right person,” she says softly, still not looking at Takagi. “But I haven’t found him yet.” Conan, having solved the murder, uses his voice changer (as Kogoro) to guide the police to the truth. The killer is the ex-wife, who removed the engagement ring from the victim’s finger to frame the fiancée. The evidence is airtight: a micro-scratch on the victim’s knuckle matching the killer’s broken nail.