I) raw data sources
A) Oricon – Charts & Sales
Decades before the US introduced Soundscan in 1991 or the UK got the DUS scanning system in 1994 Japan already had an album chart with sales mentioned explicitly. Indeed, Oricon company – named initially Original Confidence – was founded in 1967, started issuing draft charts a few months later and then officially publishing its first weekly music charts in 1970.
During the last decades, the ranking obviously evolved. Its size changed, the format (LP, CD etc.) factored in too, just like a few additional rules. One point that never changed is that sales are displayed only while a record is charting. To clarify it, below is the full discography of legendary American singer Carole King as posted by grendizer on UKMix:
1971/07/01 Tapestry # 29 , 42 weeks, 50,200 [LP]
1971/09/10 Writer # 67 , 8 weeks, 7,840 [LP]
1972/01/25 Music # 28 , 19 weeks, 25,480 [LP]
1972/12/01 Rhymes And Reasons # 34 , 12 weeks, 24,890 [LP]
1973/07/25 Fantasy # 21 , 13 weeks, 33,720 [LP]
1974/10/25 Wrap Around Joy # 73 , 1 week, 1,540 [LP]
1976/03/21 Thoroughbred # 72 , 5 weeks, 6,660 [LP]
2002/06/19 Love Makes The World # 90 , 2 weeks, 6,220 [CD]
1971/07/01 It’s Too Late # 34 , 17 weeks, 64,000
1972/02/25 Sweet Seasons # 71 , 6 weeks, 15,000
First date is the entry date on charts, second the title of the record, third the chart highest position reached, fourth the number of weeks charted, fifth the number of copies sold and then the format used to compile charts.
Seeing this list make it look like the jigsaw is pretty much completed with all information needed there. Wait a minute! If this raw data surely is valuable you will quickly understand how wrong all those figures are if you expect to read the artist overall sales in Japan.
B) RIAJ – Certifications
RIAJ stands for Recording Industry Association of Japan, the local equivalent of the US counterpart RIAA. In spite of being create way back in 1942, certifications got introduced only in January 21 1989.
Not only certifications got introduced late, they were also restricted to various rules we are going to study. Until July 2003, the Gold album award was given after 100,000 units shipped and one Platinum disc was awarded after request each 200,000 units. After July 2003 the Platinum criteria was moved to 250,000 units.
All certifications, old and new, are available and published on a monthly basis at RIAJ website.