畢業

Etymology
The Japanese entertainment/fandom slang meaning of "to graduate (to leave a group)" is a.

Verb

 * 1) to graduate; to finish school
 * 2)  to graduate to leave a group
 * 3)  to quit [a job]; to be fired
 * 1)  to graduate to leave a group
 * 2)  to quit [a job]; to be fired
 * 1)  to graduate to leave a group
 * 2)  to quit [a job]; to be fired
 * 1)  to quit [a job]; to be fired

Usage notes
Unlike its English equivalent graduate, implies not only an event but a state. Note the following example sentence:

Literally: "I have graduated for two years."