The lower interest rate environment has lowered opportunity cost of holding cash. On the contrary, not many people hold 1,000 yen banknotes or 500 yen coins, or even 100 yen coins, under the mattress. I think the increase in circulation of these banknotes and coins indicates the possibility of their continued use as a means of payment rather than as a store of value.
Based on these facts, cashless payments seem to be expanding in small-value payments where the change piles up, but cash still continues to be widely used as a means of payment.