Photo/IllutrationAn apartment in Zama, Kanagawa Prefecture, where the dismembered bodies of nine people were found in coolers and storage boxes (Yosuke Takashima)

A woman believed to be the first victim of a man who has admitted to killing and dismembering nine people accompanied him to a real estate agency to sign the lease for what would soon become a “house of horrors.”

The 21-year-old woman, whose remains were found inside the apartment, had earlier paid 500,000 yen ($4,380) into Takahiro Shiraishi’s bank account because he was required to show the agency that he had enough cash to pay seven months’ rent.

Shiraishi, 27, has admitted “wringing the necks” of victims, “drugging them unconscious” and “hanging them with ropes,” according to police.

He was arrested Oct. 31 on suspicion of abandoning a body after severed body parts, including heads, legs and arms, of nine people were found in coolers and storage boxes at his one-room unit in Zama, Kanagawa Prefecture.

Shiraishi asked to see the apartment Aug. 18 and visited the real estate agency the following day with the woman to apply to move in, police said.

The apartment unit is a 13.5-square-meter unit with a loft, and the monthly rent was about 20,000 yen, according to a person involved in the real estate business.

Shiraishi told police he had asked the woman, also from Kanagawa Prefecture, to transfer 500,000 yen into his account in advance and then showed his passbook to the agency, investigative sources said.

After screening, he signed the contract Aug. 21.

Police said Shiraishi told them that he had asked the woman to "visit the apartment anytime soon. I can pay back the 500,000 yen.”

The suspect also told police he met the woman through Twitter and had once dined with her and her male friend.

At the end of August, he invited the woman to his apartment, where he killed her, according to investigators.

The woman’s male acquaintance, unable to contact her, asked Shiraishi if he knew where she was. Shiraishi then invited him to the apartment and killed him, too, police said.

The male victim is thought to be 20 and from Kanagawa Prefecture.

A 21-year-old woman who had exchanged messages with Shiraishi on social media said he told her in September that he had “finally found an apartment with a loft which makes hanging easier.”

Shiraishi was in rush to move into the apartment unit because he “could not stand the smell of dog at his family home," according to investigative sources.

However, police suspect Shiraishi wanted his own place so he could lure women there and then kill them.