There are also showers landside in T3 (TIAT) but not T1. So if you prefer to hang out in T3 landside, where there are a lot more food / ways-to-occupy-time, another option could be buying a shower there. The Sakura lounge in T1 is fine as a waiting room but the services (besides a shower) are minimal. The food is also more light snack: rice crackers from a container and maybe a pastry.