こうはい後輩kouhai
1.
A person who has less experience or is of a younger age compared to oneself, often referring to individuals who have recently joined the same educational institution or workplace.
2.
An individual who follows in a particular field, art, or discipline, representing a new generation or successor to existing practitioners.
3.
Someone who belongs to a group, such as a school or workplace, but entered that environment after oneself, establishing a hierarchical relationship based on timing of entry.
Example:
彼は私より３年後輩です。