Hibari
He was your normal strict prefect. Always quiet and gave mean looks. Everone was a herbivore to him. Noone was a good rival. Except him. The him who helped him 'interact'' with people.
And that him was none other than Tsunayoshi Sawada.
The weak herbivore became stronger and somehow wormed its way through his stone cold heart.
He could even call him a omnivore. Always smiling and caring. So forgiving. Noone could be like him.
But he broke Hibari's heart without knowing. He didn't know that him running away from the poor prefect would hurt him so much.