Van Viet Truong died from serious injuries after he tried to help a fellow retail worker and was allegedly set upon by a group of youths at Sunshine in Melbourne's west on August 1.
Hundreds are expected to take back the space on Sunday with a peaceful gathering organised by the Vietnamese Mothers in Australia Community.
The group are calling for justice for Mr Truong along with advocating for a safer community for all residents, workers, families and small-business owners.
"Everyone deserves to feel sage in their neighbourhood, workplace and community," the event organisers said.
The death of the Hong Hung Asian Grocery store owner on Wednesday afternoon sparked an outpouring of grief across the community.
Floral tributes were laid outside the Hampshire Road store, which has been a mainstay on the strip for more than two decades, as mourners stopped to pay their respects.
Maddi Pham created an online petition on behalf of the Vietnamese community, which has reached 21,000 signatures.
"Anyone, Vietnamese or a local Sunshine residents, when they heard about the incident, they would be shocked. It is so close to you," she told AAP.
"I was just praying for Uncle to get better. I was really hoping that he would. However, people confirmed he had passed away. I was completely heartbroken."
The petition calls on judicial system to reconsider the bail for the young offenders involved, and demands safer communities.
Two girls allegedly involved in the deadly attack, both aged 14, were granted bail in a children's court on Friday.
Two boys, aged 12 and 13, appeared in the court while already on community release.
A fifth youth, a boy aged 15, who has been charged with Mr Truong's manslaughter, appeared via video link from custody and did not apply for bail.
Opposition Leader Jess Wilson said Victoria's criminal justice system was broken.
"Van Viet Truong should never have lost his life like this," she said in a statement on Friday.
"Now four youths allegedly involved are back on the streets on bail ... Van Viet Truong and his family deserved better. Victorians deserve better."
Premier Ben Carroll visited the scene on Thursday to lay flowers and pay his respects.
"There are no words for this," he said.
"As premier, there is nothing more important to me than making our streets and communities safer."