Five Japanese automakers including Subaru Corp., Suzuki Motor Corp. and Mazda Motor Corp. are each investing 2 percent in the on-demand, self-driving vehicle service set up by SoftBank Corp. and Toyota Motor Corp.

Mazda, Suzuki, and Subaru, Isuzu Motors and Toyota's compact car unit Daihatsu will each invest 57.1 million yen ($530,620) in the venture -- dubbed Monet -- in return for a 2 percent stake, the companies said in a statement Friday.

SoftBank and Toyota will each retain their 35 percent stakes in the company, which is now capitalized at $26.6 million. The latest investors join Honda Motor Co. and Hino Motors, Toyota's truck-making operations.

Honda and Hino said Friday they were making additional investments in the service but will each retain 10 percent stakes.

The venture, launched in October, plans to roll out on-demand bus and vehicle services in Japan in the next year, and a services platform for electric vehicles in the country as early as 2023 based on Toyota's boxy "e-palette" multi-purpose vehicle.

Monet is building up members as it joins the ride-sharing landscape which is dominated by startups such as Uber Technologies Inc., Didi Chuxing and Lyft Inc., as traditional automakers band together to compete in an industry which is placing growing emphasis on offering vehicle services rather than selling cars to individual drivers.

Automakers are increasingly joining forces with technology companies as well as each other as they grapple with the large investment and software expertise required to develop these new services for which demand has yet to be tested.

The new investment will see Suzuki, Mazda and Subaru deepen their partnership with Toyota, as they have already agreed to tap the r&d firepower of Japan's biggest automaker for EVs and other future vehicle technologies.

Friday's announcement comes after Monet's CEO told Reuters earlier this month it was planning to expand its investor base and start operating in Southeast Asia next year.