This is the list of number-one singles in
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
during 1991 according to Oricon Chart
[http://www.oricon.co.jp/search/result.php?kbn=js&types=rnk&year=1991 ]
References
{{Number-one singles in Japan
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
1991 in Japanese music
Oricon 1991