A fun twist on the gyaruXotaku genre. She's a pleasant gyaru. He's a traumatized/raised for murder otaku. He can't help but interpret her interest as a threat. People with low self-esteem often mistrust kindness as duplicity. This just takes the mistrust to an unreasonable level, murder.
We get a rom-com with imagined stakes: If I drop the walls of my heart enough, will I fall in love? Will I Die? School is melodramatic like that.