Miss Cinderella

Mizuho lives with her husband Yasuyuki and her mother-in-law Ryoko, who bullies her constantly over her failure to produce a grandchild. When her pet Java sparrow escapes from the house, Mizuho welcomes the chance to follow it and tracks her errant pet down to a local park. There, she finds that the bird had flown to Mitsuru, a handsome artist with whom Mizuho soon begins a torrid affair.
(Source - DramaWiki)