Spread over 2,000 square meters at the Parkson Saigontourist Plaza in District 1, it is its largest outlet in Southeast Asia.
It offers over 5,000 homeware and consumer products ranging from furniture to clothing and even cosmetics.
Nagaiwa Tetsuya, general director of Muji Retail Vietnam, said: "Vietnam is among the retail markets with the most potential in the world.
With its stable economy, constant development, young population, and rising income and standard of life, it is no surprise that Vietnam is getting ample attention from investors."
Muji was founded in 1980. Its name is short for Mujirushi Ryohin, which means "brandless quality product." In keeping with this motto, its products have no logo.
It next plans to open a flagship store in Hanoi, and then focus on the two markets to build brand awareness.
Muji said its vision is to open 10 outlets in Vietnam and consider stores in smaller provinces, depending on the economic condition, population and development status.
It will also partner with Vietnamese manufacturers and both sell their products locally and export them to other Asian countries.
The retailer has 1,029 stores in 31 nations and territories around the world.