What would be interesting is this Hebikawa is an antagonist to Shizuki, but the story never reveal her thoughts or her intention until she's ready to reveal her fangs for a coup de grâce. Make her into a lesbian with hatred against men, but is willing to make use of men without revealing her said hatred. She wouldn't mind making people (including readers) misunderstand she has feelings for the protagonist, when in truth she's aiming for Kusonoki, whom she finds to her taste. She realizes that Shizuki has to go, so she made plan to absolutely destroy his reputation, in a time where Shizuki is seemingly at the top of his life (having friends and almost/actually going out with Kusonoki). She then steals the confused Kusonoki.
Who am I kidding, it's gonna be a run of the mill romance shonen manga.