Yes, 'My Sassy Girl' is based on a true story. It was inspired by a series of blog posts that detailed the author's real - life relationship with his sassy girlfriend.
It's not based on a true story. Usually, such works are crafted by the imagination of the writers or creators to engage and captivate the audience with a unique plot and characters.
It's purely fictional. The plot and characters of 'Forever My Girl' were imagined by the writers and not drawn from real-life events. They crafted a tale to engage and move the audience within a fictional framework.