Formal — to staff
Public · Restroom · Washlet
You
すみません、この温水洗浄便座の使い方が分かりません。
すみません、このおんすいせんじょうべんざのつかいかたがわかりません。
Excuse me, I don't know how to use this washlet (bidet toilet).
Romaji: Sumimasen, kono onsui senjō benza no tsukaikata ga wakarimasen. / Reply Romaji: Hai, kashikomarimashita. Kochira de sōsa botan o go setsumei shimasu ne.
Reply
はい、かしこまりました。こちらで操作ボタンをご説明しますね。
はい、かしこまりました。こちらでそうさボタンをごせつめいしますね。
Yes, certainly. I'll explain the operation buttons here for you.
Gesture & etiquette
Pointing to the control panel of the washlet, looking confused.
In most public restrooms, there won't be staff available to ask. This phrase is more suitable for hotels, department stores, or larger restaurants. Look for illustrated instructions (often in English) near the toilet. If you press a button and water sprays unexpectedly, stay calm.