What do you call a younger girl in japanese?
No context provided
What do you call a younger girl, as an older male to a young female employee, in japanese?
kun
 is another diminutive that expresses endearment. Like "-chan", it is used for babies or young children, but is exclusively used for boys instead of girls.
What do you call a younger girl or child who is a girl in japanese?
chan
Japanese honorifics
No context provided
What do you call a young lady, also meaning big sister, in japanese?
Onēsan
Japanese honorifics
https://en.wikipedia.org/wiki/Japanese%20honorifics
The Japanese language makes use of honorific suffixes and prefixes when referring to others in a conversation. Suffixes are attached to the end of names and are often gender-specific, while prefixes are attached to the beginning of many nouns. Honorific suffixes also indicate the level of the speaker and referred individual's relationship and are often used alongside other components of Japanese honorific speech, called keigo (敬語).[1]
Japanese honorifics
Kun (君【くん】) is generally used by people of senior status addressing or referring to those of junior status, or it can be used when referring to men in general, male children or male teenagers, or among male friends.
Japanese honorifics Kun
Chan (ちゃん) expresses that the speaker finds a person endearing. In general, -chan is used for young children, close friends, babies, grandparents and sometimes female adolescents.
Japanese honorifics Chan
The Japanese language makes use of honorific suffixes and prefixes when referring to others in a conversation. Suffixes are attached to the end of names and are often gender-specific, while prefixes are attached to the beginning of many nouns. Honorific suffixes also indicate the level of the speaker and referred individual's relationship and are often used alongside other components of Japanese honorific speech. Kun is generally used by people of senior status addressing or referring to those of junior status, like an older male to a young female employee. Chan expresses that the speaker finds a person endearing. In general, -chan is used for young children, close friends, babies, grandparents and sometimes female adolescents. Onēsan is big sister, or also a young lady.