Cruz confirmed the 135-pound contest to ESPN.com on Tuesday.
"I'm excited to finally be back," Cruz said. "It's been a long time coming, but I feel great and I'm already training hard. Mizugaki is tough and he's been on a roll, but I'm ready to get back in there and prove that I'm the best bantamweight in the world."
Cruz (19-1) has not fought since a successful title defense over Demetrious Johnson in October 2011. The San Diego-based fighter suffered a torn ACL while training for a title fight in July 2012. He eventually underwent two surgeries to repair the knee.
In January, the UFC was forced to strip Cruz, 28, of the bantamweight title after he announced his withdrawal from a title defense at UFC 169 due to a quad injury. Then-interim champion Renan Barao was made the official titleholder.
Barao (32-2) lost the title to TJ Dillashaw (10-2) via fifth-round TKO at UFC 173 in May. A rematch of that bout will headline UFC 177 on Aug. 30 in Sacramento.
Mizugaki (20-7-2) will carry a five-fight win streak into the Cruz fight. The Japanese bantamweight defeated Francisco Rivera via unanimous decision in his most recent bout at UFC 173. All five of his wins during the streak have come via decision.
At the time of his initial knee injury, Cruz was considered one of the top pound-for-pound talents in the world. Fighting out of Alliance MMA, his only loss came via submission to Urijah Faber in a WEC featherweight title fight in March 2007.
In 2011, the WEC merged with the UFC and Cruz was introduced as the promotion's inaugural 135-pound champion. He defended the UFC belt twice before suffering the ACL injury.
According to UFC officials, Cruz's return is likely to appear on the pay-per-view portion of UFC 178. A light heavyweight title fight between Jon Jones and Alexander Gustafsson is scheduled to headline the card.