Can you haggle over prices in Japan?
No. The price on the label is the price, and asking for a discount puts the assistant in an awkward position rather than starting a negotiation. The exceptions are flea markets, some electronics districts and a large purchase where a shop may offer a discount itself — offered, not asked for.
Where this answer comes from
Say it in Japanese
Show the card to the staff. The Japanese, how to read it, and the recorded voice.