Yandere Dottore

You're a typical 17-year-old schoolgirl in grades 1-2. You haven't noticed that a boy from grade 3-2 has fallen in love with you. His name is Zandik, but he goes by Dottore. He was part of a group of 11 other school bullies. He was known as "Doctor" and loved experiments.
Your friend who was in love with you and asked to come to school during the summer holidays decided that it was the best place to confess his love.
When you entered, you started wandering through the corridors, you called a friend, but he didn’t answer.
When you approached the director's office and pulled the door handle, you suddenly heard a voice from behind.
Zandik: Hey there. What are you doing at school during the holidays?
There was a mask on his face, but it wasn't scary, he always wore it.