Kudo No. 2 tomb in Nara Pref.

Kudo No. 2 tomb in Nara Pref.

KASHIHARA, Japan - The Kudo No. 2 tomb, dating back to the mid-seventh century during Japan's Asuka period, in the town of Kanmaki, Nara Prefecture, western Japan, is pictured on Feb. 5, 2014. The town's education board said on Feb. 12 that a horizontal stone chamber has been discovered at the tomb.

Tile fragments found at tomb in Nara Pref.

Tile fragments found at tomb in Nara Pref.

KASHIHARA, Japan - Fragments of tiles unearthed at an ancient tomb in the town of Kanmaki, Nara Prefecture, western Japan, are pictured on Feb. 12, 2014. The town's education board said the fragments were found both inside and outside a recently-discovered stone chamber at the Kudo No. 2 tomb, dating back to the mid-seventh century during Japan's Asuka period.

Ancient stone chamber discovered in Nara Pref.

Ancient stone chamber discovered in Nara Pref.

KASHIHARA, Japan - A horizontal stone chamber, recently discovered at an ancient tomb, is pictured on Feb. 5, 2014, in the town of Kanmaki, Nara Prefecture, western Japan. It was discovered at the Kudo No. 2 tomb dating back to the mid-seventh century during Japan's Asuka period.

Empress Michiko visits 'Ashura' exhibition in Tokyo

Empress Michiko visits 'Ashura' exhibition in Tokyo

TOKYO, Japan - Empress Michiko (2nd from R in front) views Ashura, one of the treasured sculptures made during the beginning to mid-seventh century, as she visits ''The National Treasure Ashura and Masterpieces from Kofukuji'' exhibition at the Tokyo National Museum on April 4. (Pool photo)

Empress Michiko visits 'Ashura' exhibition in Tokyo

Empress Michiko visits 'Ashura' exhibition in Tokyo

TOKYO, Japan - Empress Michiko (2nd from R in front) views Ashura, one of the treasured sculptures made during the beginning to mid-seventh century, as she visits ''The National Treasure Ashura and Masterpieces from Kofukuji'' exhibition at the Tokyo National Museum on April 4. (Pool photo)(Kyodo)