A 27-year-old man was arrested Thursday for impersonating a Metropolitan Police Department officer, an alleged violation of the Minor Offense Law, after he was caught in a patrolman's uniform earlier this month while riding on a train.

Police said they arrested Katsuaki Kobayashi, a resident of Chiyoda Ward, Tokyo.

Kobayashi told police that he had wanted to become a policeman ever since he was a child, and that he had bought his costume via mail order, police said.

He said he usually wore the costume at home and while wandering around his neighborhood, and that it was the first time he had tried it on the train.

Kobayashi rode JR Joban Line and subway Chiyoda Line trains back and forth around 3 p.m. on Feb. 17, police said.

Kobayashi was making his way home on the train when an off-duty officer questioned him after noticing that he was dressed in the colors reserved for spring and autumn, not the winter color currently in use.

Kobayashi presented the officer with a business card that showed his name and the title of sergeant at a division of the MPD's Railway Police Unit, police said. He was arrested for allegedly falsely using a title.

Kobayashi was also carrying a toy gun, beat stick and handcuffs, they said.

Police quoted Kobayashi as saying that he felt good whenever passersby called out to him on the street as if he was a real officer, and he decided to wear his costume on a train.