Bonus Chapter: Roy Mustang's Observation Diary

Second Lieutenant Jean Havoc is handed the yearly task of assessing the job performance of his superior, Colonel Roy Mustang, on behalf of the Amestrian military's upper ranks. He decides the sharpest way to gauge the Colonel is to keep a running observation diary, jotting down notes on Mustang's conduct throughout the workday, and he recruits Kain Fuery, Heymans Breda, and Vato Falman to record what they see whenever he is away. Unusually for a bonus chapter, the story is told mostly through these written entries rather than illustrations, with pictures dropped in only occasionally.

The four take turns logging the Colonel's activities, with Havoc consistently straining to magnify Mustang's shortcomings while the others insist he is genuinely putting in the effort his workload demands. The notes pile up gags: Mustang buried under last-minute paperwork, burning absurd amounts of time tidying the office before inspections, looking bored through meetings while trying to hide it, and repeatedly failing to win over Hawkeye's dog, Black Hayate. Havoc wraps his report by concluding the Colonel seems capable but is dragged down by faults in his efficiency. A letter then arrives from the brass revealing that Fuery had been quietly observing Havoc in turn, reporting that Havoc neglected his own duties to trail Mustang everywhere, which costs Havoc half of that month's pay. Mustang, by contrast, is judged a loyal and devoted officer who went above and beyond, and he is awarded a bonus.

The chapter was released alongside Volume 6 in Japan on October 22, 2003. Its journal format sets it apart from the other bonus chapters, which are drawn as conventional comics.