Historical clue formulations

• Japanese port near Sapporo — 2021-07-18
• Port on Ishikari Bay — 2017-06-17
• Hokkaido port — 2015-11-08
• City on Ishikari Bay — 2012-07-20
• Japanese port — 2012-07-17
• Japanese port — 2012-06-04
• Japanese seaport — 2010-07-13
• Japanese port — 2010-06-14
• Port on the Sea of Japan — 2009-05-09
• Hokkaido seaport — 2008-09-17
• Japanese beer named for a city — 2003-03-31
• City on Ishikari Bay — 2001-09-02
• Hokkaido port — 2000-09-07
• Hokkaido city — 1999-05-21
• Northern Japanese city — 1999-02-24
• Japan's ___ Bay — 1997-01-10
• City WNW of Sapporo — 1996-06-06
• Japanese port — 1996-05-30
• Hokkaido port — 1995-03-18
• City in northern Japan — 1993-12-21