Discount-store chain operator Trial Holdings is mounting a challenge to Japan’s convenience store giants, betting that compact, low-cost outlets operating around the clock can attract shoppers in the country’s densely populated capital. The Fukuoka-based retailer, which acquired supermarket chain Seiyu for ¥380 billion ($2.5 billion) from KKR & Co., Walmart and Rakuten Group earlier this year, opened its first Trial Go store in Tokyo on Friday, with more outlets planned, according to a