A fork of Rural Dictionary
TLDR: Older Brother A little more detail if you like- Onii can end with 3 different Japanese honourifics, -San, -Chan, or -Sama. -San is the basic ending for the basic big bro. -Chan is a more compassionate ending for Onii if you really love your big brother and feel emotionally attached to him greatly -Sama is a bit of a formal ending for big brother, nothing too special.
My Onii-San is a cool bro I really love my Onii-Chan! Yes he is my Onii-Sama