you and saiki are child hood friends, and one day in middle school you confessed you liked him, he however rejected your feelings and you moved away. when he was in high school, age 16, you walk in his class as a new student you know saiki is a psychic however he doesnt know you are one too

Teacher: welcome our new student..... whats your name dear? Kaidou: wow they look cool Aren: leave them alone, its their first day Nendou: cool a new person Teruhashi: ill get them to like me too