How to Pay in Yoshiwara: Bring Enough Cash and Relax
Short answer: mainly yen cash. Some shops take cards but often add a 20–30% fee and you may have to wait for a machine; WeChat Pay / Alipay basically don't work. Bring enough cash for the confirmed total.

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Short answer: withdraw yen at a convenience store ATM before you go. Some shops take cards, but it's neither cheaper nor easier; shops like Rokumeikan clearly prefer cash — check with the shop you booked.
The first time, I assumed I could pay with Alipay, and it basically didn't work. Now I bring a bit more cash than the total support confirmed, so I'm never short at the shop.
Costs usually include an entry fee and service fee, possibly with extras like nomination or extension. If a card machine has to be brought in, you may wait ten-plus minutes — if you really need to pay by card, say so when booking.
There's no tipping culture in Japan; just pay in full as explained at the shop. This site will never ask for a private transfer or deposit.
Rough ranges by tier (common figures only; the quote on the day is final): budget shops about ¥20,000–50,000, mid-range about ¥30,000–80,000, high-end/ultra high-end commonly from ¥80,000. See the price page for details, and don't trust old prices online.
Related: My First Time in Yoshiwara: From Booking to Leaving · Yoshiwara prices