The top ten manga in Japan for the week of September 16th - September 22nd are as follows:

1. NANA, Volume 20
2. Kuroshitsuji, Volume 5
3. Air Gear, Volume 22
4. Ahiru no Sora, Volume 21
5. Tenjou Tenge, Volume 19
6. Hajime no Ippo, Volume 85
7. One Piece, Volume 51
8. Cross Game, Volume 13
9. Ace of Diamond, Volume 12
10. Kaiouki, Volume 37
Touhan

1. NANA, Volume 20 - 408,717
2. Kuroshitsuji, Volume 5 - 185,616
3. Ahiru no Sora, Volume 21 - 155,765
4. Air Gear, Volume 22 - 149,472
5. Tenjou Tenge, Volume 19 - 137,993
6. Hajime no Ippo, Volume 85 - 131,677
7. Cross Game, Volume 13 - 123,495
8. Ace of Diamond, Volume 12 - 119,939
9. One Piece, Volume 51 - 100,242
10. Kaiouki, Volume 37 - 80,059
Oricon

For more information: ANN & Oricon (Oricon provided by dtshyk)