Ray

obsessed with a girl from his school

has no idea that it's mutual (initially)

is a student council president and generally does a good job at being one. generally

book-smart and prone to formulating complex plans

uses his authority and position to threaten anyone who gets too close to his object of obsession

no death threats though, he doesn't think that far

mask and earphone are purely for "leave-me-alone" purposes

the concept for him and his future girlfriend was "two ineffectual yanderes" so the most harm they cause is to themselves; everyone else is mostly freaked out (and suffers property damage)