Sandii is described as a long-hipped woman, eurasian, half gaijin, with dark European eyes and high Asian (Mongol) cheekbones. She has dark, straight hair. She narrated many different versions of her past to X, each time saying that it was the true one. According to the first story she told to X, her father was a Hosaka executive in Tokyo, later disgraced by the company. Her mother was Dutch, and they spent summers in Amsterdam, remembering pigeons in Dam Square.
In her purse she had her makeup, a crumpled wad of new yen, a dilapidated address book held together with rubber bands, a Mitsubishi bank chip, a Japanese passport with a gold chrysanthemum stamped on the cover and a Chinese .22 automatic.
Sandii is a prostitute and spent nights down Shinjuku. According to X, She moved with the rhythm of a new age, dreamy and far from any nation. She was searching a long time for a way out, until she found him and Fox.
She walked into a bar in Yokohama, wearing a Chinese knock-off of a Tokyo designer's original. There she met X, who at that time he was after Hiroshi Yomiuri. That night they ended up in a hotel room.
The two started a relationship. They spent time in Harajuku, sometimes holding hands. They also spent time at Kamakura, laying all night on the beach. She narrated to X her nightmares, and new imagined childhoods, swearing every time that it was really and finally the true one. One of such nightes she ran back to the beach lying that she forgot her key. X went after her and found her ankle-deep in the sea, cold, shivering, with eyes far away.
Fox didn't approve of their relationship but he was delighted that she got into their way, as they could use her for Hiroshi. Before sent to her mission, he gifted her a Cray microcomputer. But he didn't detect her ambition.
The two travelled to Barcelona and stayed in the old Ritz.
A week later they flew to Vienna in order to approach Hiroshi. X brought her in the hotel that was Hiroshi's wife's favorite. She was out of sight when Maas Biolabs security flowed in to scan the hotel, and an hour later Hiroshi arrived. She managed to seduce him to leave his wife and follow Sandii to Marrakech. Sandii communicated with Fox and X despite the tight Maas security. The went to a place for coffee and kipferl. A white-haired, limping waiter, kindly worked for them and took Sandii's messages under the linen napkin. The message was relayed through Fox to X in Marrakech. They offered Hiroshi to Hosaka.
While she was with Hiroshi, he wrote for her a list of needed items in her Cray microcomputer: A freezer fermenter, an incubator, an electrophoresis system with integrated agarose cell and transilluminator, a tissue embedder, a high-performance liquid chromatograph, a flow cytometer, a spectrophotometer, 576 borosilicate scintillation vials, a microcentrifuge, ae DNA synthesizer with in-built computer, software.
But while she was in Vienna she was discovered by Maas and she sold them out. She was given an unabeled disk with the code of a meningial virus.
She met one last time with X in Germany. X kept it secret from Fox as he might not have approved. They slept in a room near the Rhine. As she slept, he went through her purse to ensure her new identity. He took a Chinese .22 gun, her Cray microcomputer and her bank chip. He replaced them with her Dutch passport and a Swiss bank chip in the same name. Then he noticed the unlabeled diskette. He ignored it and lay down with her. Next morning, as X shaved, she dumped her makeup, saying that she will try to look like a dutch.
They separated and she promised to meet in Shinjuku in a month. Hiroshi was successfully abducted from Vienna and secretly ended up in Marrakech, defecting to Hoshaka, happily in love with Sandii.
However Sandii reprogrammed the DNA synthesizer of Hiroshi's labs, with the disk from Maas. As Hiroshi punched for the overnight construction of proteins, it produced a meningial virus that klled Hiroshi and other brains of Hoshaka.
Thinking that X and Fox turned against them, Hoshaka hunted them down. X ended up hiding, with Sandii's items with him reminding of her.