ji soo never loved shin woo because of the time travel, she fall in love with man that help her jump school wall and it was teacher shin woo, and after that she meet shin woo student one after 10years when he look like her teacher shin woo so , its teacher that she loved not student
Student shin woo never get ji soo love him , in past it was teacher and in future it was also because he look like there teacher

This is best example how he himself destroyed his life now even if he end up with her he would always feel inferior in front of her knowing that she is with him because he look like her teacher that she did not know is same person,
in her heart they are two different person,

most pitiful is student shin woo that never receive love from ji soo

shin woo has first and only love ji soo but she has her first love has teacher shin woo not the student one

and he failed to save his mothers life but was success in saving ji Soo, so mother has already given him birth that she is useless but Ji soo worth....
before time travel she liked shin woo student , he himself changed ji soo first love from himself to a teacher that never existed in reality

And Ji Soo feel love for teacher kang shin woo and guilt toward student Kang shin woo
so she should not end up with any of them.
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