>>530292138
I feel like you're excluding a lot since usually ecchi focused games like Senran have (mostly) female only casts and while there are plenty of ecchi RPGs with male characters like Agarest War or Conception they might not be what you're looking for gameplay or story wise, though admittedly I haven't played a lot of these so you should probably check if they appeal to you (I really need to go through my backlog...)
Honestly I'm still not sure what you're looking for, would something tame like Atelier Ryza be fine as long as it has sexy characters? What about games having bikini and bunnygirl DLC?
If you want a random recommendation Fate/Extra CCC (PSP) is really fanservice heavy to the point where Type Moon themselves stated it's likely not getting a remake due to being too perverted for modern standards.
Stella Glow (3DS) is also noteworthy since it literally lets you impregnate the antagonist which automatically puts it above any ecchi title, it was made by ImageEpoch (devs for the Toushin Toshi remake) before they went bankrupt and is considered one of the best 3DS games.
>ENF
I think Senran Kagura would still appeal to you thanks to the clothing damage mechanics, Burst Renewal is on sale for $10 on Steam right now if you're interested.
>>530305352
I refuse to believe Hilda was designed without erotic intent.