Triple-A-size batteries, cigarette packs, and evening papers with screaming headlines are all at her fingertips. Kiyomi Okita knows exactly where they and hundreds of other items are, as well as their prices and what is flying off the shelves to whom.

Okita, a veteran clerk of 15 years at East Japan Kiosk Co., a 91-percent-owned subsidiary of East Japan Railway Co., adds color to life on the Yamanote Line, with her bright red apron and ready smile whether dispensing power drinks to tired corporate warriors or fixing schoolchildren up with Hello Kitty cell phone straps.

Okita braves the weather at a tiny, colorfully crammed cubicle inside Shinjuku Station, the busiest on Tokyo's Yamanote Line loop. During her shift, which starts at different times almost daily, she is barred from sitting to chat with her colleagues. She is allowed to go to lunch and to the restroom only at designated times. Yet the fleeting moments of interaction with customers are enough to keep her going, says the 55-year-old mother of two adult children.