i wonder if you have too many cards already? It doesn’t matter whether you have excellent record, if you have too many cards with big limits maybe the total limit/capacity has already exceeded the level of which credit card companies are comfortable with in terms of credit risk, should one day you decide to max out the limits in all cards? Unlike US which has FICO score, each Japanese credit card Cos do their own scoring based on their own system. Maybe JL card is more cautious on certain aspects than others?

Slightly OT - I have met a man who owns 50 Japanese credit cards, but then again he is probably a special case as he’s the editor of a point analysis website..