In Japan, washlet is really common. Here are words to understand the panel next to the washlet.
流す
Flush.
大
Big flush
小
Small flush
Eco小
Economical small flush
温水洗浄便座
Washlet
ウォシュレット
Washlet
止
Stop
おしり
Bottom
ビデ
Bidet
マッサージ
Massage
温水
Warm water
前
Front
後
Back
柔らか
Gentle
パワー脱臭
Power deodorization
便座
Toilet seat
音姫
Make music to cover the sound
Knowing these words you can understand the panel come with the toilet!