I dont know if the dynamic of older woman trying to resist tentation and behave accordingly, and younger one been the persistent and pushing force to getting in a romantic relationship was already made into a series, and even uploaded here, but I really would like one like that, the potencial for something deep and romantic, or just comedy and light drama/slice of life could also be great material with that kind of dynamic.
There's also And Thus I Was Picked Up By My Boss's Daughter, by the author of "Still Sick," Akashi, though it's more a comedy/drama than slice of life. I'm not generally into Age Gap stuff (nor against it, this oneshot was great), but Akashi makes it a pretty great story, imo.