This sign does not talk about savings interest rates. Such signs do not exist because such information is too embarrassing to be promoted. Please enjoy this picture of the pretty model next to information on credit card loans at Mizuho bank instead. It's the best I could do as a tangentially related picture.
The Japanese are a country of savers, and that means that banks offer them little incentive to save more than they already do. The idea that your money should be working for you, rather than you working for it, would be a baffling notion with interest rates that have to be expressed as only being to the right of the decimal point. The rates are so embarrassingly low that it's often hard to find out what they are for a particular bank, even for Japanese people. My students have tried to find the rates for their banks and it's a chore to tunnel through the information the bank offers to find them. If you live in Japan, the only way to make any appreciable interest on your savings is to send your money back home.
I won't miss the insanely low interest rates on savings.