http://www.animenewsnetwork.com/news/20 ... ekly-chart
"Hōkago Teatime," a two-CD mini-album "performed" by the characters of the K-On! anime series, became the first anime character CD release to top either the weekly album or single chart of the Oricon survey firm. The CD release sold 67,000 copies to debut at #1 on the latest weekly album chart. No other album credited to fictional anime characters has ever reached that high.