There appears to be no fixed release date, but we are advised on BROS site when it is mailed out, generally around March / June / Sept / Dec. It's a full printed magazine with full reports and lots of photos (behind-the scene).
Try and think of what you can remember for the first 3 months of this year and there will be behind-the-scene reports for it. The latest issue spans the Kouhaku, Studio Park, his birthday celebrations arranged for him at various places (Ryomaden set, radio station), various TV shows and CM shoots, noteworthy interviews, exclusive Ryomaden news, etc. Hatsukoi was released during the previous issue, so we had reports of the filming of the PV. We saw the funny photos and anecdotes that happened in each stop of the Michishirube Tour. You get the drift. In each of the recent issues, there are photos submitted by fans and a very funny cartoon drawn by his good friend Lily Franky.
This time, there is also a joint interview with him and BEGIN.
The recent issues are mostly work-related. In the past, they talked about his Crazy Horse touring activities. This is the name of his motorcycle touring group, they went all over....Hawaii, Sweden, Hokkaido etc. This is for leisure, not work-related. He's basically been riding the motorcycle from his teens. You may have seen some funny photos online which came from his travels. In fact most of the funny photos available on him came from BROS, but for me, the behind-the-scenes are the best ones.
HOW DOES BROS MAGAZINE LOOK LIKE
BROS magazine is basically written by his staff, but there will always be a personal report written by himself - "Domo, Fukuyama desu" (Hi! This is Fukuyama), where he talks about his personal feelings, like a diary to his fans. Sometimes, as you can see from the translations, he talks about how he writes his music and the influences he had. Certain captions are in his handwriting.
The magazine itself has evolved over time. If you go to the auctions site, you'll find pictures of the old ones. Count #86 issues quarterly issues.....that's 20 years. They were in the form of a newspaper at the beginning and I'm not sure if at any point they were bi-monthly or so.
Information emailed to you upon request