This is the list of number-one singles in Japan during 1991 according to Oricon Charthttp://www.oricon.co.jp/search/result.php?kbn=js&types=rnk&year=1991
January 7 (No information) January 14 "Ai wa Katsu" (愛は勝つ) Kan January 21 January 28 February 4 February 11 February 18 "Oh! Yeah!/Love Story wa Totsuzen ni" Kazumasa Oda February 25 March 4 March 11 March 18 March 25 April 1 April 8 "Lady Navigation" B'z April 15 April 22 "Wednesday Moon" Hideaki Tokunaga April 29 "Lady Navigation" B'z May 6 "Eyes to Me" Dreams Come True May 13 May 20 "Kiss" Princess Princess May 27 "Please" Shizuka Kudo June 4 "Love Train" TMN June 10 "Anata ni aete yokatta" (あなたに会えてよかった) Kyōko Koizumi June 17 June 24 July 1 July 8 "Beat Emotion" Tomoyasu Hotei July 15 "Anata ni aete yokatta" (あなたに会えてよかった) Kyōko Koizumi July 22 "Neo Bravo!!" Southern All Stars July 29 "Donna Toki Mo." (どんなときも) Noriyuki Makihara August 5 "Say Yes" Chage and Aska August 12 August 19 August 26 September 2 September 9 September 16 September 23 September 30 October 7 October 14 October 21 October 28 November 4 "Shabontama" (しゃぼんたま) Tsuyoshi Nagabuchi November 11 "Alone" B'z November 18 November 25 "Wild Heaven" TMN December 2 "Boku wa kono hitomi de usowotsuku" (僕はこの瞳で嘘をつく) Chage and Aska December 9 "Piece of My Wish" Miki Imai December 16 December 23 December 30 "Sore ga Daiji" (それが大事) Daiji-man Brothers Band
References Oricon No.1 Hits 500. Clubhouse (Japanese: クラブハウス). 1998. ISBN 9784906496136. vol 2 (1986~1994).