male high school student; boys' high school student
Refers to a male student attending high school. The two English gloss are essentially synonymous; 'boys' high school student' can imply a student at an all-boys school, but in practice the term is used broadly for any male high schooler.
That male high school student wakes up early every morning to study.
Some male high school students were chatting happily at the station.
Refers to a female high school student, the counterpart to 男子高生.
General term for a high school student, without specifying gender.
女子高生 refers to a female high school student, while 男子高生 refers to a male one.
Compound of 男子 (だんし, 'male') + 高生 (こうせい), an abbreviation of 高校生 (こうこうせい, 'high school student').