Aspiring a job associated with trains that he's always loved, he seeks employment with the national railroad in hopes of becoming a driver and then set for life. But, during his student OJT (an internship system while still in school) puts him in the railroad public safety division instead of the driver division. He has no particular skills that stand out, and tries to get past his internship without any hitches, but he gets tossed around every which way by the members of Patrol Four (the Tokyo Central Railway Public Safety Bureau's Fourth Patrol Brigade) and becomes involved in various incidents.

A huge hater of men, she has a very extreme and spirited personality that boasts, “Anyone who molests people on trains should be shot and killed right there!” Anytime an incident happens, she pokes her head in faster than anyone else, and is often the troublemaker for Patrol Four. An exceeding lover of guns due to the effects of having a police officer as a father, and her shooting skills as well as her martial arts skills are top-notch.

A beautiful and intelligent girl born in a high-class family who is very mild-mannered. She doesn't have any motor skills nor stamina, so she tends to drag the Patrol Four team down, but she is a genius of memorization and can even memorize the entire train schedule of Tokyo station. Her grandfather apparently was on the board of directors for the national railroad, but it is a mystery as to why she chose the public safety division.

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A typical muscle-brain that trumps everyone at physical tests, but is terrible at any written exams. His trademark attire, despite not being official uniform, is the knife-proof vest and special billy club. He may be a simple man, but is very reliable once an incident happens, as he will risk his life to face the criminals head-first.

Naoto's classmate and second year student at Kiryu Railroad High School. What you would call a lover of railroad sounds, she travels all over the country for the sounds of various trains. Good friends with Naoto through their love of trains, and understand each other very well. She desires to be assigned to dining car attendants for her student OJT.