This is the best successful yuri grooming doujin I've ever laid eyes on.
It's just wholesome enough to wash away the bad taste of the grooming from an excessively young age and the incest. Also the face the older sister made when she realized she was successful made me laugh out loud.
Except it's not grooming. The older sister had to be maybe 2-3 years older, and knew nothing about sex when they started. It was probably several years until she started feeling sexual feelings from it, and by that time the kissing itself was normal to both of them. Grooming is a deliberate action with a plan in mind, which there is no evidence of here. And again, the people calling anything about this story "wholesome" is rather disturbing.
i'm used go reading incest in this site but i felt a little uncomfortable with this one, it's true that i felt uncomfortable while reading incest lots of times