A new addition to Yamazaki's extremely popular Lunch Pack series is a variety of 4 different stuffings: yakiniku, yaki-soba, egg and potato salad. Very simple idea, but this brand is one of the biggest in Japan - available in every supermarket and convenience store, pretty good and cheap. ランチパック ヤマザキ
http://www.yamazakipan.co.jp/
Photo is a web capture for explanatory purposes, copyright belongs to the company.