| Location | Osaka Pref. |
|---|---|
| Shape | Keyhole-shaped mound |
| Mound length | 114 m |
| Period | Mid–late 5th c. |
The burial mound with the largest armor find in Japan (over 80 pieces including 24 short cuirasses and 28 helmets). Located in Mihara Ward, Sakai City; 114m long, rear circle ~62m, front section ~72m wide. Dated mid to late 5th century. The armor cache suggests a highly militaristic occupant—perhaps a military commander positioned between the Mozu and Furuichi groups. The armor was deposited en masse on the ritual platform at the mound's waist section. National Historic Site.Archaeologically significant for its exceptional armor finds. The 24 short cuirasses represent the largest single-mound armor discovery in Japan, providing first-rank evidence for understanding ancient Japanese military organization. The excavated armor is on display at the Osaka Prefectural Chikatsu-Asuka Museum and the Sakai City Museum. Its location exactly between the Mozu and Furuichi groups has fueled theories that the occupant played a military role between the two power centers. Residential development surrounds the mound, but the burial mound itself is well preserved.
Excavations by Sakai City Board of Education (around the time of National Historic Site designation). The most significant finds — the armor cache — were deposited en masse in the ritual platform (tsukuridashi) at the mound's waist section: over 80 pieces of weapons and armor including 24 short cuirasses (tanko) and 28 helmets with front ridges (the largest single-mound armor find in Japan), plus iron swords, iron arrowheads, beads, and horse gear. Excavated armor is on display at the Osaka Prefectural Chikatsu-Asuka Museum and the Sakai City Museum.