Go check the airport English web page (do a search or wait for someone to post it here!). If you don't have access to an airline club that has showers, there are facilities where you can take a shower at a reasonable charge -- Y500 (about USD4) for 30 minutes. You can also hire a room to take a nap.

Sounds like United with that schedule, there are showers for use in the Red Carpet Club which you can use as a RCC member, customer travelling in C or F, or *gold on another *A airline.