"Thank you! Heisei rice ball / sushi 100 yen sale" is being held from April 23 to 26 at each Seven-Eleven store.
This is a special sale where rice balls and sushi for less than 160 yen (tax included, the same applies below) are 100 yen, and rice balls and sushi for 160 yen or more and less than 200 yen are 150 yen. Packed rice balls, packed sushi (multiple pieces), and frozen rice balls are not eligible.
Also, if you register for the Seven-Eleven app, you will receive a coupon that will give you an additional 10 yen discount on rice balls and sushi. Items under 160 yen are 90 yen, and items over 160 yen and less than 200 yen are 140 yen.