The country that the child had been abducted to is a signatory, but Japan isn't.
From the economist.com
A year later, the Dutch government became a signatory to the Spitsbergen Treaty.
From the en.wikipedia.org
One other signatory is Kent Parry on behalf of the Davis Council of Governments.
From the sltrib.com
Switzerland is signatory to all relevant international human rights instruments.
From the en.wikipedia.org
The United States, which disavowed the Kyoto treaty in March, is not a signatory.
From the washingtonpost.com
But the pact still requires ratification by the 25 signatory nations'parliaments.
From the stltoday.com
El Salvador had copyright relations as a signatory of the Mexico City Convention.
From the en.wikipedia.org
Jacob of Nisibis is recorded as a signatory at the First Council of Nicea in 325.
From the en.wikipedia.org
Esther Lior, the wife of extreme right-wing Rabbi Dov Lior, was another signatory.
From the cnn.com
More examples
Signer: someone who signs and is bound by a document
A signature (from Latin signare, "to sign") is a handwritten (and sometimes stylized) depiction of someone's name, nickname or even a simple "X" that a person writes on documents as a proof of identity and intent. The writer of a signature is a signatory. ...
One who signs or signed something
(Signatories) people authorised to sign cheques on behalf of an organisation. At lease two signatories are normally required for all payments and the trustees should approve the signatories. See also authorisation of expenditure, segregation of duties and financial controls/procedures.
A signatory is a person who signs a document. For instance, if you are making an application and sign a form, you are the signatory.
A gold mining company or operation using cyanide for gold recovery, a manufacturer of cyanide destined for use in gold recovery, or a transporter of cyanide used in gold recovery, or the parent corporation of such companies, that has committed to follow the Code and has paid the required fees ...
A country that wishes a draft resolution to be put on the floor and signs the draft resolution to accomplish this. A signatory need not support a resolution; it only wants it to be discussed. ...
A signer, with another or others; a person whose name is being inscribed on a document who requires assistance in doing so.