Already former top-ranked store chains are sliding into bankruptcy as a decline in spending that has lasted for half a decade hollows out their customer base. The closed signs went up last year on Sogo after 170 years as Japan's top retail name, while the fourth ranked group, Mycal, has also filed for bankruptcy. Daiei, the country's largest supermarkets chain, has sought protection from creditors as it tried to avoid sinking under the weight of bad debts.