Friends suck, and trusting someone is just setting yourself up. That's the lesson Mei Tachibana learned after her heart was ripped out and only a shell was left where a girl used to be. But unlike so many, she found an easy solution: she'll never make another friend. Ever. Okay, maybe that's not as easy as it sounds, but it's worked for Mei. Or at least it did. Until handsome, charming and annoyingly popular Yamato Kurosawa came along. Because for some freakish reason, he seems to like Mei. He even gave her his phone number! As if she would ever call him. Except she did. But only because she needed help. Still, he came. He actually came. And now things are getting way too complicated. Mei's no princess in a tower. She's not waiting for a knight in shining armor to rescue her. So why did he have to kiss her and confuse everything? And why are those three little words so hard to say? Between heartbeats, behind trembling lips, and unspoken with every breath, the specter of betrayals past, future and present now haunt them both in SAY "I LOVE YOU."

Mei Tachibana is a high school student. Due to a traumatic incident when she was a kid, Mei has been unable to make friends or have boyfriends. By mistake, Mei then injures the most popular male student named Yamato Kurosawa. Somehow, Yamato Kurosawa likes Mei Tachibana and tells everyone unilaterally that Mei is his friend. One day, Yamato Kurosawa saves Mei Tachibana from a stalker by kissing her. From that kiss, their love story begins.