Makes complete sense, I'm not sure why I've been glued to the saddle throughout my sessions. Will check out the trial program and definitely investing in a pro bike fit soon. Thanks for the tips and recommendations!
Specialized in shinjuku rents out saddles if you want to try them, it's 500-550 yen per day and I did find a saddle that fits me. I got one of their romin saddles. They also have a machine that will measure your seat bones and recommend a saddle for you.
Trek in Roppongi will also lend you a saddle for free, although it might be because I bought my bike there and I'm a customer, so your mileage might vary.
I still have to get up every 20-30 min on the trainer for couple of minutes to get blood flowing to my ass bones. But at least the saddle doesn't try to kill me anymore. Also you might want to try using chamois cream which is a life saver for me and good pair of bibs.