Here’s an ad from the January 23 1936 edition of the Toronto Daily Star for a new grocery store:

Before becoming a Monarch Marketeria, 623 Danforth was a branch location of the Adams furniture company, as that was what was listed in the 1936 Toronto city directory. It turned out that the Monarch Marketeria chain did not last through 1936: in the 1937 directory, 623 Danforth Avenue was part of the Dominion grocery chain, and the other two Monarch Marketeria branches were now part of the Miracle Marketeria chain.
623 Danforth remained a Dominion store for a few years, as the 1946 directory lists it as such. The 1956 directory lists it as part of the IGA chain. It is currently known as the Pape Market and is part of the Foodland chain.