Please answer the following question: Information:  - The , sometimes translated as The Chronicles of Japan, is the second oldest book of classical Japanese history. The book is also called the . It is more elaborate and detailed than the "Kojiki", the oldest, and has proven to be an important tool for historians and archaeologists as it includes the most complete extant historical record of ancient Japan. The "Nihon Shoki" was finished in 720 under the editorial supervision of Prince Toneri and with the assistance of  no Yasumaro dedicated to Empress Gensh.  - The Hidaka Main Line (  Hidaka - honsen ) is a railway line in Hokkaido operated by Hokkaido Railway Company ( JR Hokkaido ) , between Tomakomai Station in Tomakomai and Samani Station in Samani , running through the coast of Hidaka Subprefecture .  - The Ainu or the Aynu (Ainu  "Aynu"; Japanese: "Ainu"; Russian: "Ajny"), in the historical Japanese texts Ezo/Emishi/Ebisu or Ainu, are an indigenous people of Japan (Hokkaido, and formerly northeastern Honshu) and Russia (Sakhalin, the Kuril Islands and formerly the Kamchatka Peninsula).  - The , also read as Ashihase and Shukushin, were a people of ancient Japan, believed to have lived along the northern portion of the coast of the Sea of Japan. The term Sushen, rendered , is found in Chinese records, but is annotated as Mishihase or Ashihase in Japanese language documents, which should have developed into *"Mishiwase" or *"Ashiwase" in Modern Japanese if the word had survived in colloquial speech.  - The is one of the constituent companies of Japan Railways Group (JR Group), and is often referred to using its official abbreviation of . It operates intercity rail services in Hokkaido, Japan. The company introduced Kitaca, a smart card ticketing system, from autumn 2008.  - The Japan Railways Group, more commonly known as , consists of seven for-profit companies that took over most of the assets and operations of the government-owned Japanese National Railways on April 1, 1987. Most of the liability of the JNR was assumed by the JNR Settlement Corporation.  - History. Hokkaido () was settled by the Ainu, Nivkh, and Orok before recorded history. The "Nihon Shoki", finished in 720 AD, is often said to be the first mention of Hokkaido in recorded history. According to the text, Abe no Hirafu led a large navy and army to northern areas from 658 to 660 and came into contact with the Mishihase and Emishi. One of the places Hirafu went to was called , which is often believed to be present-day Hokkaido. However, many theories exist in relation to the details of this event, including the location of Watarishima and the common belief that the Emishi in Watarishima were the ancestors of the present-day Ainu people.    What entity does 'hidaka main line' has the relation 'country' with?
A:
japan