A Story About a Grandpa and Grandma Who Returned Back to Their Youth S01E03 - Grandpa Turns Old Again
Summary:
Ever since Shouzou and Ine turned young again, they've had dreams of a mysterious hourglass. One night, Shouzou has the dream again and something unexpected happens. The next morning, when he wakes, his body has returned to that of an old man.
A Story About a Grandpa and Grandma Who Returned Back to Their Youth S1E3 Screenshot