Meanings

official letter (esp. in internal company corresp.)

correspondence

microblog

fast and easy

crisp

public lodging house

public lodging house

public lodging house

simplified registered mail

simplified Chinese character

portable toilet

short letter

simplified version

simplified naturalization (for spouses of Japanese nationals, non-nationals born in Japan, etc.)

(written) correspondence

fragment of a historical document

Postal Life Insurance

Postal Life Insurance Bureau

very easily

at one's discretion