Private onsen in Osaka
A bath you have to yourself: no other bathers, and usually no tattoo problem either.
Is there a mixed onsen in Osaka?
Not one we have found. Mixed bathing (konyoku) survives at mountain, riverside and seaside baths, and we have not recorded one in Osaka. If what you want is to bathe together as a couple or a family, a private onsen is usually how it is done in Japan: the 3 below have a bath your group uses alone. Where Japan’s mixed baths are, and what to wear
Day trips from Osaka
The same list for places you can reach from Osaka and be back the same day.