Both have the same basic plot where it involves high schoolers doing a man's job where it puts the grown ups to shame, it also has the same trigger happy female character and a sweet female character. Romance wise both MC doesn't have any romantic direction at all. However, the setting where different cu'z Rail Wars was set in some alternate place where Japan's Railroad system remains public, while in Amaburi it was set in some theme park where fantasy was the main theme. Also, in Rail Wars, the MC has a harem competing for its affection, while the MC in Amaburi doesn't have a harem to begin with, in fact there is no competition between the two main females character's for the MC's affection.  read more
Both have the same MC who somehow got trust into a grown-up's job, where the stakes are high and the pressure is on, both also have the same female character who is trigger happy, except in Amaburi the female character there carries a bigger gun-two to be exact, while in RW the female character there carries a 6 shot revolver.
The same plot where it involves high-schoolers who does the kind of work that should be done by an adult . It also, has the same Male Main Character, who is reluctant to be put in charge of something big, it also has the same gun touting female character who is very aggressive and a bit mean, it also has a female character who is sweet and is nearly identical in their illustrations. The difference were, in Rail Wars, the theme of the anime was about trains, while in Amagi Brilliant Park's theme focuses on the magic of theme parks.  read more
Both are action series involving something that must be protected. For Toshokan Sensou, books & for Rail Wars!, railways & trains. Both also have have an opposing faction. For Toshokan Sensou, Media Betterment Committee & for Rail Wars!, RJ.
This is similar to Rail wars as both anime series are ecchi and and both anime's have similar visuals. Another similarity is that the main characters are students. Also the voice actors who play the roles of Haruka Koumi and Aoi Sakura in rail wars also play supporting characters in high school dxd.
Rail Wars really reminds me of Gin of Saji because of the way they explain the process of the career. It also revolves around friendship and a slight romance. Gin no Saji ended up being a great anime despite it's about farming. Rail Wars also gives that vibe.