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 1990 according to Oricon Chart.
[http://www.oricon.co.jp/search/result.php?kbn=js&types=rnk&year=1990 ]
References
{{Number-one singles in Japan
1990 in Japanese music
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 ...
Oricon 1990