Mystery plant could be Goldstrike Acuba japonica. They are a nice plant for texture / color in the garden. Very hardy. Drought resistant and easy care. Your tomato plants are doin great.
It shouldn't be too long now, until the mystery is finally revealed. As soon I'll be getting tomatoes from this plant.
I have little tomato plants coming up in my raised beds now. It happens every year. I never seem to get all the tomatoes picked before one or two get overripe and hit the dirt. I don't fool with them, though because I need to grow hybrid, disease resistant types and the seedlings would probably not be capable of fighting off diseases.
Nice looking tomatoes @S-H ! Hoping for a great crop! I also don't. I do save seeds from favorites. Roma VF has some disease resistance, and my saved seed plants do fine. Unfortunately there aren't many good hybrid dwarf varieties, the mainstays of my slicing tomato garden. I save seeds for those. I use a cardboard mulch so there is no splashing of bacterial spores and fungal spores from the soil, and train upright. Also drip irrigation. So far that does the trick for me in our dry summer climate.
I think the best thing anyone anywhere at anytime can do with tomatoes, regardless of whatever type they are - Is sun-dry them! Because not only does this concentrate the flavor, but also makes them last for a very long time in storage. Just remove all seeds before doing that, as too many tomato seeds can cause kidney stones to form...