Flea market app operator Mercari Inc. said Monday it will list its shares on the Tokyo Stock Exchange's Mothers section for start-up companies on June 19.

Mercari is known as a rare Japanese "unicorn" — a startup valued at more than $1 billion. Its market capitalization is expected to exceed ¥200 billion ($1.83 billion) in its initial public offering.

The Tokyo-based e-commerce firm, which started business in 2013, operates a smartphone app that allows people to buy and sell used clothing and other items easily.

As its marketplace has gained popularity nationwide, Mercari has been working to create tougher rules to counter the sale of stolen or illegal items.