Shouzou and Ine Saitou have been happily married for as long as they can remember. Even in their old age with wrinkles and cracking limbs, the strength of this love is evident by their precious bond. And then, randomly one day, they wake up to find they are young again!

Despite their newfound youthful and attractive bodies, Shouzou and Ine remain the same as ever. Jiisan Baasan Wakagaeru follows the young old couple as they go about their daily lives, spend time with family, and defy the expectations of the youngsters.