Here is the weekly single CD sales ranking for May 24th - 30th. (non-anime songs are omitted.)

*3, 80,272 *80,272 Angel Beats! OP & ED "My Soul, Your Beats!" & "Brave Song"
*8, 18,443 *18,443 Yojouhan Shinwa Taikei OP "Maigo Inu to Ame no Beat"
10, 12,564 *12,564 Arakawa Under the Bridge OP "Venus to Jesus"
11, 10,865 *10,865 Shimajiro Hesoka OP "Boku wo Sagashite" by Toyosaki Aki
13, 10,145 *46,713 Angel Beats! "Thousand Enemies"
16, *9,384 *53,512 Angel Beats! "Crow Song"
21, *5,999 *79,518 Gintama: Shinyaku Benizakura-hen OP "Bakuchi Dancer"
23, *5,138 **5,138 Yojouhan Shinwa Taikei ED "Kamisama no Iutohri"
24, *4,795 121,531 K-ON!! OP "Go! Go! Maniac"
29, *4,029 108,625 K-ON!! ED "Listen!!"
32, *3,831 **3,831 Kaichou wa Maid-sama! ED "Yokan"
37, *2,915 **2,915 Kaichou wa Maid-sama! OP "My Secret"
43, *2,387 **8,144 Katekyo Hitman Reborn! OP "Listen to the Stereo!!"
47, *2,355 **2,355 Baka to Test to Shoukanjuu "Kinoshita Hideyoshi Only Single"
50, *2,083 **2,083 Katekyo Hitman Reborn! ED "Familiar"
52, *1,940 **1,940 Uragiri wa Boku no Namae wo Shitteiru OP & ED "Uragiri no Nai Sekai Made" & "Aoi Ito"
59, *1,812 *10,907 Heroman OP "Roulette"
67, *1,514 **1,514 Utawarerumono "Bokudake no Tabiji" by Koyama Tsuyoshi
69, *1,416 **9,135 Mayoi Neko Overrun! OP "Happy New Nyaa"
78, *1,177 **1,177 Senkou no Night Raid ED "Mirai e..."
85, *1,132 **1,132 Break Blade OP "Fate"
86, *1,106 *15,970 Hakuouki OP "Izayoi Namida"

Source: Youtaiju

ref. the first week sales of K-ON!! themes
Go! Go! Maniac 83,400 copies
Listen!! 76,558 copies