A great manga about the struggles between world leaders that is settled between games of Mahjong. Almost every character is based off of a real person who is (or was) a real world leader or important in some way. These battles of wits in Mahjong become increasingly intense and there are equivalent stakes, including the lives of people. It is ridiculous in many ways and has some political commentary that doesn't get too serious. It also got turned into a 3 episode OVA, the first of which is based off of one of the chapters, the other two are new plots created specifically for the OVA. The manga is still ongoing, but it's in the "final battle" right now and it seems to be towards the climax, although it's hard to gauge.
Any manga that has Vladimir Putin as a main character is good in my book.
Go read it now.
