Artifacts excavated from Hirao Iridadzuka and excavation survey materials

　Near the border between Hirao, Inagi City, and Asao Ward, Kawasaki City, there is a mound called Nyujozuka. Nyujo generally refers to entering meditation or the death of a sage. Kukai, the founder of the Shingon sect, preached that by entering into meditation, we wait for the arrival of Miroku Bodhisattva. Based on this teaching, monks of Shingon Esoteric Buddhism were ordained in various places since the Middle Ages. They chanted sutras while alive and underwent rigorous training to wait for the arrival of Miroku Bodhisattva (Miroku Bodhisattva) by entering a mound and being buried.
The Nyujozuka in Hirao was excavated in 1966. From the inscriptions on one of the excavated tablets, a monk named Choshin entered the priesthood on August 15, 1536. It was revealed that it was a mound. The mound has a rectangular shape with each side measuring approximately 10.8 m, and inside the mound there is a main body measuring approximately 1.8 m x 2.1 m. Pillars were erected at the four corners of this place to create a board-walled room, and it is thought that Nyujo training was carried out inside this room. The top of this main part was covered with a layer of clay, and on top of that a mound was built by mounding soil.
A sword excavated from the mound that is thought to have been used for rituals, 44 bronze coins brought over from China, and iron nails that are thought to have been used to build the main body of the building. A total of 103 items have been designated as Inagi City's tangible cultural properties, including 7 items from Tetsukugi and 51 items from excavations.

　The artifacts excavated from the designated Nyujo-zuka include 44 bronze coins, 7 iron nails, and 1 iron sword. It's 52 points.
Copper coins are coins imported from China, and there are some with illegible characters, such as Tang coins, Song coins, and Ming coins. The most common types of coins excavated are Song dynasty coins (10th to 13th century). These copper coins are thought to have been used during the Nyujo ceremony. During the Middle Ages, the minting of coins in Japan was not active, and only coins imported from China were in circulation. It is thought that Toraisen, which was commonly circulated at the time, was used in the Nyujo ceremony.
Iron nails were discovered along with carbonized wood around the main body. The length is between 8 cm and 13 cm, and the deterioration has progressed considerably, but the nails with a square cross section were used when building the main part of the facility with a board fence. It is thought that it was a used nail. The iron sword measures 24.5 centimeters in length and 2 centimeters in maximum width, and is thought to have been used for rituals held in the main body.

These materials were created during the excavation survey conducted in August 1952. The materials include 2 tablet rubbings, 14 surveyed drawings of ruins and remains, 33 survey photographs, and 2 drafts of manuscripts, for a total of 51 items. It's a point. The tablet rubbings are the rubbings of two of the nine tablets excavated from the main part of the temple. One of the tablets, a manuscript of a tablet, reads, ``August 15th, 5th year of the Tenbun era, Hinoesaru, Choshin Hoin, Nyujo Shonin. )" is engraved on it, and is a valuable document that shows the date of construction of the Nyujozuka and the name of the monk who was ordained. Measured drawings (jissokuzumen), actual measurement drawings (jissokuzu) of the entire mound (jissokuzu), floor plan of the remains (ikoheimenzu), cross section of the soil layers (dosodanmenzu), excavated artifacts (shutsudoibutsu) ( These include floor plans of stone monuments, etc., measured maps of iron nails, and so on. The survey photos include a panoramic view of Nyujo-zuka, a cross-section of the soil layer, the state of the excavation of the tablet, the state of the clay layer, and the state of the excavation of the copper coin. Photos of the condition, full view of the main body, and condition of the floor of the main body. The manuscript draft appears to be a draft of the manuscript for the investigation report, and includes information such as the location and size of the Nyujo-zuka, the facilities of the main body, and the state of excavation of the tablet. I am. A total of 15 sheets of 400 characters each. These excavation survey materials, together with the items excavated from Nyujodzuka, are used to learn about the actual state of Nyujodzuka and the status of excavation surveys in the Middle Ages. It is considered an indispensable and important document.