MangaGamer has started its
Winter Sale, which runs until December the 25th. 20 games have been discounted with 7 surprise games that will receive discounts on the 25th.
Additionally, all the games released in 2015 will net you tripple amount of MG points if you buy them until the 4th of January. You can use MG points to get discounts on your other purchases.
It also must be noted that MangaGamer has recently changed its stance on DRM and has been removing it from their titles for some time now. There are very few DRMed titles left on MG store. Only 4 sale titles out of 20 still retain DRM:
eden* PLUS+MOSAIC
Princess Evangile
d2b vs DEARDROPS -Cross the Future-
Cho Dengeki Stryker