This is a Japanese (or English) language manga (comic) or a magazine featuring multiple manga series.
Yuu Yuu Hakusho was recently re-released in a new large format and with new art on the covers. Since this edition was complete in only 15 books, an additional "Characters" book was added (so that the publisher could keep their promise of two books a month!). The "Characters" book is really thorough, giving all the information you'd want to know about the main characters, and a lot of information you might not have known about a whole lot of minor characters -- enemies, one-shot characters, etc. Black and white, 196 pages, all text in Japanese.