Several Japanese investors sued the brokerage arms of SBI Holdings Inc., Rakuten Group Inc. and Monex Group Inc., adding to the fallout in the world’s third biggest economy over losses on Credit Suisse’s riskiest debt.

In a suit filed Monday to the Tokyo District Court, two plaintiffs demanded around 42.7 million yen ($290,940) in compensation from SBI Securities Co., Japan’s biggest online brokerage, alleging it sold the notes while offering incorrect explanations about them.