Have you ever been to Kabuki Springs & Spa? It's an amazing spa in japantown. If you get a massage there (I think around $80) you also get unlimited time to soak in the wonderful hot tubs, steam room, sauna, etc. OR, if you want super cheap, forgo the massage and just spend $20 to go to the spa...a soak in their beautiful hot tubs will be incredibly relaxing. The whole place is beautiful and clean and indulgent. One caveat: you have to be okay with being totally naked in front of other women (check their website to see which days are for women only and which are men only...tues is co-ed with bathing suits).