I don't think it's a bush. It looks like a type of Narcissus to me and would grow from bulbs. It will probably die back in a few weeks and reappear next spring.

Welcome to GoY
I agree with Hywel,
these are a type of narcissus [common name is just a type of daffodil].
as to which one I don't know.
If you could take a close up of a flower it would help.

I agree it does appear to be a narcissus. I think it might be N. Sir Winston Churchill. Have a look at this link. https://www.rhs.org.uk/plants/details%3Fplantid%3D3585

I am not sure that it is a Narcissus. If it were it would be in the 'tazetta' category with its multiheaded white flowers. Against this the cups are very tiny compared withe the petals, there is far too much foliage and it looks as if a whole bagfull of bulbs have been planted in one hole.
Nothing else to suggest, though.

I just blew up the photo and I can see what Bb says about the cups being very small. If you google 'photos of tazetta daffodils' you might be able to recognise one as being the same as you have. Before I enlarged your photo I thought it was a double flower. Winston Churchill is a double flowered tazetta. Do let us know what it is when you find out as I am intrigued. A close up photo of one of the flowers might trigger a name by another member. I dk how long you have had this growing in your garden, the excess of leaves might be accounted for by the plant producing bulbils, small bulbs, which are not yet big enough to produce flowers. Welcome to Goy.

Another quick question for you. Does the plant die back completely shortly after flowering or does it stay green all through the year.

This was already growing in my garden when I purchased my home. It wasn't there last June but just sprouted up about 4 months ago and rather quickly to this full bloom in 2 months. The flowers smell similar to a gardenia and have 3 to 4 flowers sprouting from one stem.

Then it sounds as if it is narcissus bulbs, Ikerri. As a thought, I wonder if a previous owner dumped a pot of 'Paperwhite' narcissus in the ground after having them as a houseplant - they are fully hardy and no reason not to grow in the garden.

Thank you all for your welcome and input. When I looked up the Narcissus Tazetta, it resembled that the closest due to the multiheaded flowering.