Kumamoto Airport Parking is for free for up to 30 minutes!
空港駐車場は３０分まで無料！
(¥100 for 30 minutes to 2 hours; ¥150/hour for 2 hours to 5 hours; ¥800/day 5 hours to 3 days, and ¥700/day over 3 days)
When it is very crowded over weekends and holidays, it will save time and be easier to find a space if you head straight to the area nearest the international terminal, rather than the domestic terminal.
混んでる時には、国際線ターミナル側！
When you pay for parking, use the automatic adjustment machine so that you can take a less crowded lane when leaving the parking area. The fare might be cheaper, too!
帰りは事前精算機利用でスムーズに！
When you eat at an airport restaurant (over ¥3,000), parking is free for up to 2 hours.
空港内レストラン利用（￥３０００以上）で２時間無料
（阿蘇くまもと空港情報マガジンより）