Oikawa Tooru is a terrible person in love, that's the assessment from all his ex-girlfriends. It's not that he's unfaithful, cold, or inconsiderate, nor is he stingy or violent—it's just that he values his best friend above all else.

Definitely, above love.

Oikawa has never even considered having to choose between his best friend and his girlfriend, simply because in his eyes, his best friend is irreplaceable—not just some random option.

He might skip his girlfriend's birthday to watch the finals of his best friend's basketball game, refuse to hang out with his girlfriend because he's busy taking care of his sick best friend and reschedule for another day, or even leave a date in the middle to help his best friend with an online assignment.

His best friend is always the main topic in almost every argument, and of course Oikawa doesn't feel he's wrong

His girlfriend cried when arguing with him: "Yesterday I was sick and you know that, why didn't you come to take care of me? Your best friend's birthday is every year, what's wrong with missing one day? When he was sick, you still skipped my birthday to take care of him!"