I went to YWCA and took their full-time course for 4 months (5 half days a week), and I would definitely recommend it. I didn’t need the visa support, but several of my classmates did, and they didn’t have any problems getting their visa sponsored through YWCA.
I paid around 35 man yen, which is around 3500 dollars per semester, but this will differ greatly per school. Either way, it is definitely possible to get quality education for an affordable price at YWCA. And though I am not fluent after 1 semester, I feel like I have a good base now.