In October 1909, Sekino, a Japanese expert who launched a second historical investigation under the commission of the Korean government under the Japanese colonial rule, reached Pyongyang with two assistants, Tani and Guriyama. At that time, they were first told by Sarakawa, the Japanese president of the (Pyongyang Ilbo), that there were many unknown tombs clustered in Daedong-myeon, the southern coast of the Daedong River. Sekino and his party changed their schedule and immediately turned to it. Indeed, very old tombs were scattered. They immediately went into the cave to pick up two of them and find out the inside. Sekino, who was directing the excavation of ancient tombs with vague expectations, was surprised to find that Han Dynasty culture mirrors, weapons, and earthenware were buried while decorating reality with jeon (bricks). But he soon realized the reason. It was a great discovery of the ancient site of the Nakrang period, where the Korean people who enjoyed a very amazing culture migrated about 2,000 years ago, and the completely forgotten underground treasure trove of Hanbohwa. It will be revealed later, but there were thousands of Nakrang tombs spanning the suburbs of Pyongyang and Hwanghae-do. Sequino's investigation team excavated two Nakrang Ancient Tombs and planted many artifacts in the fall of the following year, and in October 1911, a third investigation excavation was conducted near Sarriwon. At this time, the tomb of Daebangtaesu Jangmui and the Saturn, which was thought to be the site of Daebanggun, were discovered in a place called Dangtoseong Fortress. They also went in September 1913 to investigate the remains and tombs of Jinnampo and Bongsan-gun.It was excavated and rich burial items such as a piece of waxang, blowfish, bronzeware, pottery, lacquerware, jade stoneware, and weapons were obtained. They carried all the excavated items to Japan as if it were natural. In April 1912, an exhibition organized by the Department of Architecture drew attention at the Department of Engineering at the University of the East Economic Bureau. The focus was on the relics excavated from Nakrang Ancient Tombs displayed and unveiled for the first time in Room 3 (Chosun Branch). The following is the contents and clear details of the exhibits introduced by Japanese archaeological magazines at the time. "It is so abundant that Sekino assistant professor, Dani, and Guriyama party brought it three times from Joseon that it is difficult to store it one by one, but if you point out the important things, Hangyeong, Ojujeon, Jeung (Siru), Dangtoseong discovery, Misan-myeon, Bongsan-gun." These are relics from the discovery of Anhakgungji and the discovery of the tomb of King Hanwang in Gangdong." In addition to relics excavated from Nakrang Ancient Tombs and historical sites in 1912, Sequino and others dug under the pretext of academic research at Daegaya Palace and Ancient Tombs in Goryeong, Gyeongbuk, 500 stone pillows and small Silla Buddha statues found in Seoak-dong near Gyeongju. It is believed that these relics are still kept at Tokyo National University of Technology. And in Volume 1, published by the Japanese Government-General of Korea in 1916, we can only check some of the illegal artifacts of that time, such as Tokyo, weapons, limbs, rings, onggi, Jubal, and jeon (excerpt from Nakrang Ancient Tombs in Seokam-dong, Daedong-myeon). When these printed artifacts were introduced as photos in (the Chosun Historic Walk), they were already made into a fait accompli that they were collections of the College of Engineering at Dongguk University. Sequino says in a later investigation report that the 1909 historic investigation (Narang Ancient Tombs and others) was commissioned by the Korean government, as if it were a pure request, but it was only a superficial form. At that time, Japanese forces were already in full control of the Korean government. Therefore, it was one of the so-called politics of the Ministry of Government-General to appoint a historical investigation and give him freedom to dig ancient tombs and carry relics to Japan at will if necessary. The nominal department of the Korean government, which granted him permission to destroy legitimate ruins, loot relics, and illegally take them out, was the Takji Department. However, at that time, the de facto unauthorized person in the Takji Department was the Japanese Vice Minister Arai. And it was Vice Minister Arai who devised one of the three-dimensional invasion plans to have Sekino, then an assistant professor at the University of Economy, investigate the historical sites across Korea. After the annexation of Korea and Japan took place the following year, of course, it was at their disposal. It was in October 1916 that an official excavation team led by Sekino excavated 10 Nakrang tombs in the south of the Daedong River (Daedong-myeon) near Pyongyang and excavated unexpected and enormous relics and irreparable burial items. At this time, the 10 tombs excavated were numbered from No. 1 to No. 10, and the current National Treasure No. 89 "Geumje Diocese" (Director of the National Jung-ah Museum) was excavated from No. 9 at that time. This parish, which was imbued with delicate pure gold work, was a world-class discovery showing the extreme of Han Dae culture. However, such sensational discoveries at the same time led to rumors that "a bunch of pure gold treasures were buried in Nakrang Ancient Tombs," followed by outlaws' out-of-control theft. The Japanese called the Nakrang Ancient Tombs in the Daedong-myeon area "Jung Chang-won (a repository of Japan's famous ancient oriental art)," and everyone and I tried to take out the "unmanned" treasure in it. A Japanese man later recorded the situation as follows. "After Dr. Sekino and his party excavated hundreds of valuable burial items in Daedong-myeon in 1916, interest in Nakrang relics gradually spread to the private sector, and in 1922, a group of people who robbed Goryeo porcelain near Gaeseong turned to Nakrang Ancient Tombs, and the worst egg cave era developed." However, it is the above story. By the time Sekino began to investigate Nakrang Ancient Tombs, the theft and looting of Japanese people in Pyongyang had already begun. The facts are recorded in Sequino's investigation report. At the beginning of the investigation, he wrote that he had already seen the robbers collected by a Japanese resident named Yamada, and after a while, he was told that valuable bongs with letters such as "Nakrangtaesujang" and "Jeonggamjang" were discovered at the point where he presumed to be Nakranggunji. It is also confirmed that around that time, Sekiguchi, the prosecutor of the Boksimwon in Pyongyang, also had a bongni engraved with "Chosun superiority" in Toseong-ri. The era of Daenanggul beyond the imagination of Nakrang Ancient Tombs, which Japanese outlaws and evil collectors robbed directly or indirectly or manipulated from behind, refers to a period of four to five years from 1923. In the following retrospective of a Japanese, we can get a glimpse of the amazing inner story of that time. With the development of the Great Turbulent Era, the sudden prevalence of Nakrang fever in Pyongyang (Japanese society) became prevalent like an infectious disease, and the reputation of Nakrang was resonated in the world. At that time, the authorities' identity was not as severe as today (1934), but rather, some people in relationship occupied the excavated items (stealing items) in the tomb ahead of the general public, and in Daejeong 13-14 (1924-1925), one or two won were given to Pyongyang citizens (the words centered on the Japanese)." The previous witness continues to inform the specific state of the time. In severe cases, Lee, a government official, proudly took a life-sustaining worker to Baekju, dug up the middle of the burial mound from above, and pulled out dazzling burial items. During this period, the most excellent were in the hands of natural private collectors. However, after a while, when the robbers realized that selling only Pyongyang collectors was not a big profit, they put a line with Hosaga (collectors) in Gyeongseong and Kyoto and secretly stole one of the robbers to pay two or three times as much as a collector in Pyongyang (Pyongyang, Paljeon Changmyeong and Legendary) in 1934. On the other hand, the Japanese behind the scenes were rarely caught and punished. The situation was so great that such remarks were made in the minutes of the Government-General's Historic History Committee held on August 2, 1926. "We must lure those who steal and punish those who do it severely. And then, the people who discovered themselves should be punished. It is bizarre and impossible if it is true that only the discovered minorities are exempted from punishment." However, Japanese criminals behind the vicious background, who were always in contact with local and central (Seoul) power collectors, were always in a safe position. In addition, their systematic and direct theft and financing continued until the 1,900 falling tombs ran out of burial supplies, which was unprecedented large-scale looting of artifacts in the world. A later survey report records, "Of the 1,400 Nakrang tombs, only about 140 were avoided from being robbed." How many valuable artifacts and national treasure-class cultural properties were excavated during this disastrous period of Daenangul and entered the hands of the Japanese? It is an unpleasant mystery that cannot be imagined. However, some important robbers of the time are known as records and photos, one of which is the same type (about 40cm in diameter) of the Three Years of Glory (B.C.), a relic of the Warring States period introduced by Sequino in 1923. At that time, the owner was Dorikai, who was the principal of Pyongyang Middle School. In mid-October 1922, a Chinese worker excavated from the railway construction site in Seongyo-ri (Narang Ancient Tombs) across the Daedong River near Pyongyang, and a Japanese named Hashimoto intercepted it and brought it to Dorikai, the principal of Pyongyang Middle School where his son attended. However, Sekino did not believe the story at face value.
"It was also displayed in middle school because a Chinese worker, the discoverer of the same kind, brought another broken mirror to Principal Dorikai, but it is not known where it was discovered at the same time." (The same time, 1923)