Billionaire Hiroshi Mikitani said that his Rakuten Group is keen to sell more bonds to Japanese investors to help diversify funding that has been focused on overseas debt markets.

"Bond investors are very, very confident or building their confidence in our business,” Mikitani, 59, said in an interview, pointing out that the yields sought by investors when buying the e-commerce conglomerate’s debt had declined "significantly.”

Market pricing indicates that views on Rakuten are improving after years of losses and a stretched balance sheet. Successfully tapping the domestic bond market would add to this momentum, though many challenges remain.