Quick, easy and convenient online booking. Present your passport and IDP, provide some personal info, pay and you're good to go. Insurance options available. I booked the most basic car and it exceeded my expectations. Worth noting that although it is ETC equipped, the actual card is not provided. GPS voice navigation has an English mode although you will have to key in destinations using hiragana and then choose the right kanji. Although helpful most of the way, the GPS navigator was not up to date with the multiple road closures around Aso, and we got quite lost so always have a Plan B. This is less than a 5-minute walk from Kumamoto station. Would book again.