The erotic massage scene in Osaka is confusing as hell. There are some “sexy massage” spots around the red light districts. Those are a bit hit and miss, but Lynn (http://nanba-mens-esthe.com/) at 11-28 Nanbasennichimae is worth a recommendation. Most of the erotic massage in Osaka is about the enigmatic health services. That sounds very pretentious and serious but it’s just escort business under a different name. Let’s say you book a girl at Remote Spa (https://remote-spa.jp/) and you take her to a love hotel. Love hotels are usually equipped with mats and stuff for the Nuru massage.
There used to be soaplands in Osaka, but as of 2018 they are not a thing anymore. You still have spots like Club Amour (https://club-amour.com/) at 2 Chome-6-6 Nishishinsaibashi, which explicitly denies full service. It’s a so-called “mat health” or “mat play”. You get a bath, a massage, and a blowjob. It’ll cost you $200 for a session. By the way, the discounts don’t apply to foreigner customers. As often in Japan gaijin, foreigners, get a different treatment, to put mildly what many will see as straight-up discrimination.