Tokyo Vice, by Jake Adelstein

While this isn't quite manga, it goes into so much depth about Tokyo, Japan, and Japanese culture that I have to recommend it.

Jake Adelstein is an American who went to college in Japan and then became a reporter for the Yomiuri Shinbun, one of Japan's largest newspapers (one chapter gives a great description of the entrance exams and training that he went through to do it). There, he went into the Vice Beat area, and began covering the seedy aspects of Tokyo and nearby Saitama, including yakuza (the Japanese mafia) activities, murders, host club scams, and a group of robbers who once stole an entire ATM machine using a forklift.

In the process, Adelstein learns a lot about the workings of the police, the give and take between police and reporters, and especially about yakuza-related crime (this is because one of his stories gets his life threatened by the head of one of the biggest yakuza groups--in fact, it's the reason Adelstein and his family are currently living back in the United States). He also writes a lot about Japan, including real-life examples of sempai-kohai relationships, host clubs (most are not, in fact, run like Ouran's), and basic details about Japan that are really interesting: I've been reading manga for nearly 11 years, and I was well aware of the public bathhouse system in Japan, but I had no idea that there are also coin-operated showers! (At the time of Adelstein's writing, 100 yen would get you five minutes of hot water.)

Since one of my favorite manga, Sanctuary (by Sho Fumimura and Ryoichi Ikegami) is about yakuza and politicians, I had to pick this up. And I definitely learned a lot about yakuza from it, and even some about Japanese politics: I had no idea that the reigning party in Japan, the (quite misnamed and very conservative) Liberal Democratic Party, was founded by yakuza money given to the creator of the LDP--apparently this is an open secret in the country! The things you learn.

What fascinated me the most, however, was Adelstein's breakdown of the different districts within Tokyo. I knew the main names--Shibuya, Shinjuku, Roppongi, Akibahara--but I didn't know much about the different aspects of them. The one I knew most about was Akibahara, and that's because any otaku worth their salt has to know the electronics/manga/doujinshi/otaku playground. (Plus, a good chunk of Genshiken takes place there, so.) But Adelstein goes a lot more in-depth about the areas, including what businesses (mainly shady) tend to be where and what each district is most famous for (for Roppongi, it's apparently catering to foreigners. No wonder I never see that place much in manga).

Tokyo Vice contains a ton of information about Japan, including a whole lot about the side that you don't see much in manga (at least, outside of seinen, or manga geared toward adult men), on top of all the vice beat stories. If you're interested in more details of Japan and Japanese culture to better understand the background behind your favorite manga, this book is a great place to start.