Reservations

Generally speaking booking a reservation (予約 yoyaku), as far in advance as you can is preferred by shops and girls. You can book via a website or the phone. If you are not fluent in Japanese please reserve using the foreigner friendly sites like [CanReserve] and [YoasobiHeaven]. If shops ask if you are a foreigner please inform them. Do not try to pass yourself off as Japanese.

Various Reservations System:

Call CityHeaven: You can book a reservation online, but they will call you to confirm/finalize.
SMS caskan.jp - example this one does not call you by default, and instead uses text messages, you might get by with a Japanese sounding name, frequently used by esthe systemscrisp
Chat Bot bodyspa2008 this uses a bot with some translation services, not an exact middleman, responses are slow but the price might not go too far up various online or inquiry forms - these are usually via email or LINE only, and they will not call.
Middle Man: yoasobiheaven for most of you we really suggest booking thought YoasobiHeaven or CanReserve. They are both middle man services that do take a cut honestly without knowing Japanese this should be your route. Yes you will pay more. Generally all booking is done via chat, either wechat, Line, or their own chat.