Here is the weekly manga sales ranking top 30 for Jan 12th - 18th.

Rank/ This week's sales/ Total sales/ Title
*1, 170,171 *,170,171 Hayate The Combat Butler vol.18
*2, 121,781 *,121,781 Kekkaishi vol.23
*3, *80,318 *,*80,318 Hotaru no Hikari vol.13
*4, *50,552 *,*50,552 The World God Only Knows vol.3
*5, *45,957 *,*86,576 7Seeds vol.14
*6, *42,029 *,*42,029 Honmani Kanjani ∞!! vol.4
*7, *41,715 *,*41,715 Yamamoto Zenjirou to Moushimasu vol.4
*8, *38,833 *,*38,833 Kimi no Iru Machi vol.3
*9, *38,176 *,192,852 Bakuman vol.1
10, *34,708 *,205,635 Eyeshield 21 vol.33
11, *32,586 *,*32,586 Saijou no Meii vol.4
12, *31,255 *,*68,644 Mei-chan no Shitsuji vol.1
13, *31,255 *,*64,836 Mei-chan no Shitsuji vol.2
14, *31,021 *,*31,021 Kinkyori Renai vol.3
15, *30,862 *,188,728 To-LOVE-Ru vol.12
16, *30,557 *,194,123 Natsume Yuujinchou vol.7
17, *30,399 1,017,218 Fullmetal Alchemist vol.21
18, *29,546 *,*29,546 Shibatora vol.10
19, *28,842 *,*58,645 Mei-chan no Shitsuji vol.3
20, *28,536 *,*28,536 Shinyaku Kyojin no Hoshi Hanagata vol.12
21, *27,268 *,*27,268 Q.E.D. Shomei Shuryo vol.32
22, *26,730 *,*54,119 Mei-chan no Shitsuji vol.4
23, *26,111 *,*88,299 Mei-chan no Shitsuji vol.7
24, *25,541 *,*70,196 Mei-chan no Shitsuji vol.5
25, *25,403 *,*75,964 Mei-chan no Shitsuji vol.6
26, *24,517 *,*24,517 Tegami
27, *22,941 *,*33,694 Heart no Kuni no Alice ~ Wonderful Wonder World ~ vol.2
28, *22,357 *,*22,357 JoJo's Bizarre Adventure Part 6: Stone Ocean vol.10
29, *21,553 *,311,331 Koukou Debut vol.13
30, *21,224 1,588,381 One Piece vol.52

Additional Info1: A live action TV drama series based on "Mei-chan no Shitsuji" was started on January 13th.
The official website of the TV drama

Additional Info2: "Tegami" is a collection of short stories of Tanikawa Fumiko.
Tegami on Amazon Japan

Additional Info3: An official fanbook of "Strike Witches" ranked the third in the weekly general book sales ranking.
1, Speech Collection of Obama
2, Manual For The Preventions of New Influenza
3, Strike Witches Official Fanbook Complete File
Source: Scan of Yomiuri Newspaper

Last week's ranking: Japan's Weekly Manga Ranking For Jan 5 - 11
Source: Oricon Comic Ranking