if this is a book title it could be anything but the literal translation is
Ritorusantakurōsu to biggusantakurōsu
Santa Claus is spelled サンタクロース in Japanese and it is said like this, Santakukoru. サンタクロース (santakuroosu)
You may say 'santa kurousu,' written: サンタクロース
In Japanese, Santa Clause is translated to Santakukoru.
You may say 'imouto.'
hiko
oki inu
chisai kitsune
tora no hotondo
Japanese just use kodomo as in child
'Little fire' translates toå°ã•ãªç‚Ž (chiisana honoo) in Japanese.
小熊(koguma)
The term 'little sister' could be translated as 'imouto', to say 'my little sister' you could say 'watashi no imouto'. But remember, if you are going to refer to someone else's little sister, you must say 'imouto-san', 'san' being the honorific, which are a key element of the Japanese language and etiquette.