Is there an arrival lounge/suite in KIX? No.

What there is for you is a 24 hour airport lounge, the Kanku lounge, as jib71 has mentioned. Actually, the manga cafe is only a part of the lounge. ksandness is talking about the same thing. While normally it is 300 yen to enter the open area and an additional 300 yen for the shower, they offer people who only want to use the shower (and not the seating or internet) use for only a fee of 500 yen for 15 minutes. Be warned that although the shampoo, conditioner, and soap are free, a towel is an additional 210 yen. I always brought my own, so I don't know if you get to keep that towel (although I suspect you do, just like at the onsen).

How is it? It's not as fancy or as big as the ones in ANA lounges, but it gets you wet and that's its job, right?

Both links mentioned, http://www.kansai-airport.or.jp/en/s...index.html#_04 and http://www.kansai-airport.or.jp/lounge/ refer to the same Kanku lounge. It's on the 2nd floor, north; which is also the domestic departures floor. It's right across from the book/music store. You will also arrive on the north end, but on the 1st floor. Just take one of the escalators or elevators in front of you when you exit customs.