Historical clue formulations

• Japanese native — 2017-12-23
• Japanese native — 2012-04-08
• Japanese aborigine — 2008-08-07
• Japanese aborigine — 2006-10-14
• Aborigine of northern Japan — 2003-05-18
• Aborigine of Japan — 2001-10-23
• Hokkaido native — 2001-06-16
• Hokkaido native — 2001-04-01
• Hokkaido native — 2000-11-21
• Hokkaido native — 1999-12-03
• Hokkaido people — 1998-08-30
• Hokkaido people — 1997-08-30
• Hokkaido native — 1997-04-20
• Japanese aborigine — 1995-02-01
• Japanese aboriginal — 1993-12-28