1. Old urchin: Express grandpa's innocent and lovely side.
2. Fairy: Express grandma's innocent and lovely side.
3. Little old man: It can be used to describe grandpa's appearance or personality.
4.ATM: It can be used to describe that grandma often gives financial support.
King: It can be used to describe grandpa's authority or position.
6. breeder: it can be used to describe that grandma often prepares food for her family.
7. Society My Big Brother: It can be used to describe grandpa's social status or influence outside.
8. Maruko: It can be used to describe grandma's appearance or personality.
9. Drag bottle: It can be used to describe the role of grandparents in the family, and it is a drag bottle for the family.
Of course, these are some remarks. You can choose the right name according to your preference and your relationship with your grandparents.