FAQ
Common questions
What is a colophon?
The colophon (奥付) is the page at the back of a Japanese book that records the printing date and print number. Okufu prices first printings: look for 第1刷 and a date that matches the first run.
Why isn’t “初版” or “first edition” enough?
Seller text saying 初版, “first edition,” or a cover price mark gets reused on later printings. The colophon date plus 第1刷 is what counts.
What does the price band mean?
The band is the middle of sold Volume 1 first printings: lower quartile to upper quartile, not a single fair price. Obi (帯), sealed, and graded copies stay out of the book band.
Where do the sold prices come from?
Yahoo Auctions closed listings, PayPay Flea sold listings, and Mercari sold listings. A row counts only when it is this series, Volume 1, and a first printing.
How does the currency switch work?
Prices are stored in yen. The menu converts them with fixed rates from the snapshot date (BoJ / ECB). They are for reading the page, not live FX.
What do the tiers mean?
Tiers place a series on the popularity–price chart. S+ and S sit high on both axes; lower letters are selective or watch-only. The Method page has the full rules.