I believe it is sayanara......however I don't know how to spell it.
Otasha de! "Stay well!" is my preference.
take care always
"Take care."
'Always 'in Japanese would be 'itsumo'. 'Take care' can have several expressions like 'okarada wo odaijini' (take care of your body)(polite form) or 'ki wo tsukete' (be careful, take care) or 'youjin shinasai' (be careful, take care, be cautious). You can put 'itsumo' at the beginning of any of these expressions as you like.
Take care would be "fais attention" or "prends soin de toi" in French. Take care would be "fai attenzione" or "prenditi cura" in Italian.
You care for a Japanese baby the same way that you care for any other baby.
First the Japanese, then the communists; one take's care of a task, "one bite at a time."
You may say 'ki wo tsukete ne/kudasai.'
You may say 'ki o tsukete (kudasai/ne).'
Ki o tsukete kudasai, or more informally, ki o tsukete (ne).
Yoroshiku onegaishimasu is literal of "please take care of me" said to say "Nice to meet you"
私の世話をしてください。
It means please be careful, or take care of yourself