| Akihiro Inoue | Director | 17 Dec 1991 | 29 Jun 1994 | Japanese | 82 years |
| Andrew David Smith | Director | 18 Jul 2012 | 14 Feb 2014 | British | 50 years |
| Andrew Marc Jones | Director | 28 Jul 2005 | 6 Nov 2009 | British | 58 years |
| Benjamin Toby Grose | Director | 13 Oct 2009 | 30 Aug 2022 | British | 57 years |
| Eugene Francis Doyle | Director | 5 Jan 2001 | 13 Aug 2007 | Irish | 69 years |
| Hiromi Yanagisawa | Director | 3 Nov 1994 | 14 May 1996 | Japanese | 77 years |
| Hiromi Yanagisawa | Director | 14 May 1996 | 28 Sept 1999 | Japanese | 77 years |
| Humphrey James Montgomery Price | Director | 5 Jan 2001 | 28 Jul 2005 | British | 84 years |
| John Dering Nettleton | Director | 17 Dec 1991 | 5 Jan 2001 | English | 82 years |
| Kenji Kajiwara | Director | 24 Oct 1997 | 12 Aug 1998 | Japanese | 77 years |
| Kentaro Imanishi | Director | 22 May 1995 | 25 May 1995 | Japanese | 79 years |
| Kunihiko Matvsoka | Director | 17 Dec 1991 | 29 Jun 1994 | Japanese | 91 years |
| Kunio Ohsawa | Director | 17 Dec 1991 | 5 Feb 1994 | Japanese | 89 years |
| Lucinda Margaret Bell | Director | 14 Jul 2006 | 19 Jan 2018 | British | 62 years |
| Mark Andrew Stirling | Director | 28 Jul 2005 | 6 Nov 2009 | British | 63 years |
| Martin Francis Mcgann | Director | 26 Feb 2003 | 7 Oct 2005 | British | 65 years |
| Masaaki Kokubo | Director | 14 May 1996 | 22 May 1998 | Japanese | 71 years |
| Masaaki Kokubo | Director | 22 May 1998 | 10 Mar 1999 | Japanese | 71 years |
| Masahisa Nagano | Director | 24 Oct 1997 | 22 May 1998 | Japanese | 85 years |
| Masahisa Nagano | Director | 22 May 1998 | 10 Mar 1999 | Japanese | 85 years |
| Masaomi Bando | Director | 24 Jun 1994 | 10 Nov 1994 | Japanese | 81 years |
| Michael Anthony Wilson | Secretary | 17 Dec 1991 | 10 Apr 2001 | British | - |
| Nagamichi Sengoku | Director | 17 Dec 1991 | 5 Feb 1994 | Japanese | 81 years |
| Nakaki Yoshida | Director | 17 Dec 1991 | 28 Sept 1999 | Japanese | 82 years |
| Patrick Lionel Vaughan | Director | 5 Jan 2001 | 3 Mar 2001 | British | 79 years |
| Paul Christopher Ronald Wates | Director | 17 Dec 1991 | 5 Jan 2001 | British | 88 years |
| Philip John Martin | Director | 13 Oct 2009 | 31 Oct 2016 | British | 69 years |
| Philip John Martin | Secretary | 10 Apr 2001 | 31 Oct 2016 | British | - |
| Rodney Clutton | Director | 17 Dec 1991 | 5 Jan 2001 | British | 80 years |
| Shingo Arima | Director | 18 Jul 1994 | 22 May 1998 | Japanese | 87 years |
| Tadashi Hirano | Director | 22 May 1995 | 24 Oct 1997 | Japanese | 83 years |
| Taizo Koike | Director | 17 Dec 1991 | 26 Mar 1993 | Japanese | 89 years |
| Takao Saso | Director | 15 Aug 1994 | 15 May 1995 | Japanese | 87 years |
| Takao Saso | Director | 14 May 1996 | 24 Oct 1997 | Japanese | 87 years |
| Takashi Kano | Director | 10 Mar 1999 | 28 Sept 2000 | Japanese | 76 years |
| Takehiko Kinoshita | Director | 23 Nov 1994 | 15 May 1995 | Japanese | 83 years |
| Toshihiro Kusakabe | Director | 28 Sept 1999 | 28 Sept 2000 | Japanese | 73 years |
| Valentine Tristram Beresford | Director | 28 Jul 2005 | 6 Nov 2009 | British | 61 years |
| Yoshihiro Mitsui | Director | 23 Nov 1994 | 15 May 1995 | Japanese | 69 years |
| Yoshihiro Mitsui | Director | 22 May 1995 | 14 May 1996 | Japanese | 69 years |
| Yoshio Takeuchi | Director | 28 Sept 1999 | 28 Sept 2000 | Japanese | 77 years |