小さいタトゥーがあるのですが、入浴できますか？ — I have a small tattoo, but can I use the bath? (Onsen · Etiquette, Formal — to staff, JLPT N4)

Gesture & etiquette

Briefly indicate the arm or area where a tattoo might be.

Be prepared for a "no" answer, especially at traditional onsens. Some places require covering with a waterproof sticker, others have a blanket ban. Do not enter if explicitly forbidden.