Aruna booked his place in the round og 16 on Friday after beating Kanak Jha of the United States to finish second behind Korea’s Lee Sangsu in Group A.
Mizutani, 28, was among the top eight seeds who were not involved in the group stage games.
Mizutani won bronze in the singles event and silver in the team event at the Rio 2016 Olympic Games.
He won the 2010 and 2014 ITTF World Tour Grand Finals.
Africa’s other representative, Omar Assar of Egypt, was drawn against world champion and number one seed Ma Long of China.
Winners in the round of 16 will progress into the quarter-finals which will also take place today (Saturday).
The competition will end on Sunday.