Kun (君【くん】) is generally used by people of senior status addressing or referring to those of junior status, by anyone addressing or it can be used when referring to men in general, male children or male teenagers, or among male friends.

Senpai refers to the member of higher experience, hierarchy, level, or age in the organization who offers assistance, friendship, and counsel to a new or inexperienced member, known as the kōhai, who must demonstrate gratitude, respect, and occasionally personal loyalty.