Ikebukuro, a large commercial and entertainment district of Tokyo, boasts the second-busiest train station in the world (after Shinjuku, another district of Tokyo) with 2.7 million passengers on an average weekday in 2004. The kanji for Ikebukuro literally mean pond bag, and a plaque outside of the train station suggests three possible origins of the name:
- In the northeastern part of Ikebukuro there once was a lake shaped like someone holding a bag.
- There once was a large number of lakes in the area of various sizes (thus implying a "bag full of lakes").
- Long ago a turtle came out of a lake carrying a bag on its back.