Bain Capital is collecting bids for Oedo Onsen Monogatari, operator of about 40 hot spring inns and resorts across Japan, with first-round proposals submitted by investment funds and SoftBank Group Corp., sources have said.

The U.S. investor is seeking to sell the Oedo Onsen Monogatari group for more than ¥100 billion ($932 million), said the sources, who asked not to be identified because the information isn't public.

Bain Capital is also considering an initial public offering for the hot-spring business, the people said. The investment group bought the Japanese company in 2015 for about ¥50 billion, according to a report by the Nikkei newspaper at the time.

Investors have shown plenty of appetite for hot-spring assets as well as real-estate investment trusts that invest in such leisure facilities. SoftBank-owned Fortress Investment Group has already snapped up about 100 hot-spring establishments and hotels, and has indicated that it will spend as much as ¥400 billion on the sector over the next four years.

Nomura Holdings Inc. is advising Bain on the sale, according to the sources. A representative for Bain did not immediately respond to a request for comment. Representatives from SoftBank and Nomura declined to comment.

Oedo Onsen Monogatari is designed to evoke the atmosphere of Tokyo during feudal times, when it was called Edo or sometimes Oedo ("big Edo"). The group also runs a REIT that invests in hot-spring properties, returning 8.6 percent since its inception in 2016.