Challenge
Why do the students think Kenji is frightening? Clues ポイ捨(す) てしといて全(まった) く悪(わる) びれてない they believe he littered and shows no remorse 怒(おこ) ってた先生(せんせい) ニラんでた they say he glared at the teacher who was scolding him What does the speaker mean? They think he littered without remorse and glared at the teacher. 悪(わる) びれてない says he showed no shame, and ニラんでた adds that he stared the angry teacher down. He apologized for littering but the teacher stayed angry. 全(まった) く悪(わる) びれてない means the students saw no sign of guilt or apology. He reported another student for throwing away the can. The students believe 札月(ふだづき) だった, that Fudazuki was the one who littered. He became frightened when the teacher confronted him. The students say Kenji glared at the teacher, which makes him appear defiant rather than frightened. He quietly picked up the can and left. Their account describes unapologetic littering and a glare at the teacher, not cleaning up. He scolded the teacher for littering. The teacher was angry about the litter, while the students believe Kenji committed the act.
The students believe Kenji littered, showed no guilt, and glared at the teacher who confronted him. Those details fit the delinquent image Kenji wants, so they conclude that he is genuinely scary.