According to Oricon, the theme songs of K-ON!! occupied the top 2 of the weekly single CD ranking for April 26th - May 2nd. The OP "GO! GO! MANIAC" and the ED "Listen!!" have won the top and the second, respectively. It's for the first time in Oricon's 42-year-history that a single CD of anime character wins the top in the weekly ranking. Hokago Tea Time has become the third female singer(s) who took the top 2 of the weekly single CD ranking. The previous record was made 26 years ago.

The album CD of the first series "Hokago Tea Time" had won the top of the weekly album CD ranking last July.

Weekly Single CD Ranking for Apr 26 - May 2
*1, 83,400 *83,400 K-ON!! OP "GO! GO! MANIAC"
*2, 76,558 *76,558 K-ON!! ED "Listen!!"
*7, 14,200 *14,200 B Gata H Kei OP "Oshiete A to Z"
*8, 14,115 *47,279 Gintama: Shinyaku Benizakura-hen OP "Bakuchi Dancer"
*9, 12,977 *12,977 Fullmetal Alchemist: Brotherhood ED "RAY OF LIGHT"
19, *5,376 **5,276 Tales of Symphonia: Tethe'alla Hen ED "Inori no Kanata"
27, *3,052 112,547 Nintama Rantaro OP "Yuki 100%"
29, *3,009 *10,674 Hakuouki OP "Izayoi Namida"
36, *2,451 *13,195 Ichiban Ushiro no Daimaou OP "REALOVE:REALIFE"
43, *1,935 *32,053 Heartcatch Precure! OP "Alright! Heart Catch Precure!"
44, *1,803 *18,760 Detective Conan Movie 14: The Lost Ship in the Sky ED "Over Drive"
49, *1,763 **1,763 Fairy Tail OP "ft."

ref. the first week sales of K-ON! first season themes
Cagayake! GIRLS 61,608
Don't Say "lazy" 66,910

Source: Oricon, Youtaiju, Youtaiju2