The translated chapters catch up to the ending even though this manga ended years ago.
This specific series may not be a headliner, but I found it more enjoyable than most.
To my surprise, the MC is one of the few (rare) individuals who chooses to stay old. He was somehow reborn at his original age and refused the opportunity to become younger. Knowing this feat makes me shake my head in agreement.
The MC is fairly OP but not to the point where it's unbalanced. He has impressive levels of discipline and displays virtue at any opportunity. Something like seeing the light in the dark even if it's just a speck or minimal chance. Story-wise, it's just usual adventures and it ends before you know it.
Sure Jiisama may not have been a headliner, yet the aspects of an ideal MC shine bright.