A Dog Love

He was walking his Akita dog in the park. The weather was so pleasant!  or How pleasant the weather was!  How pleasant a weather! He saw so many couples walking happily. He went and sat in the shade of the old sycamore looking at the beauty of the world. Why couldn't he enjoy the happiness?! The dog saw the black and white people and the world they owned. He was happy beside the young boy. He noticed the verdure above his head and wished he could climb up and find someone among the thick branches because people down on earth had disappointed him, but if he had done so, the dog would have left too. After all, the dog was all he was left with.
He had read about the moments of epiphany in books but he never believed such a thing could happen in real life.
Oh, what a beauty! She was wearing a white dress and a white scarf. They had already one thing in common. She was also walking her dog. It was a bulldog. In a moment their eyes met each other and - here we go - the arrow was shot. It was love at first sight.
"I don't think we need the dogs anymore; why don't you get someone to take care of your Akita?"
"Don't Won't you miss your bulldog?"
"Not as long as I have you."
After the baby was born, he asked his friend to take care of his dog. The dog kept coming back to his old friend, though he kept ignoring him.
"I don't think I love you anymore"
The dog saw her in a/her/the white dress and scarf and black shoes while (as) she was leaving. (maybe left would be better here)
(Inspired by the movie "Hachi: A dog's tale")

Your english is very good!  Only a couple of things: verdure is a word, but a rare one.  "greenery" or just "leafy branches", or some other description would be more common.  Also, there are lots of "he"s and "him"s that I got lost in a couple of times and I had to re-read to see if it was refering to the man or the dog.  Anyway, nice writing!