The Chemistry Between a Background Alpha and the Main Character's Love Interest

I'm Zhou Yi, a top through and through, just like my name suggests. Fifteen years after transmigrating into an ABO world, I discovered that I'd actually transmigrated into a book. Luckily, I differentiated as an Alpha and came with a gorgeous childhood-friend love interest. Sure, he's an A too, but what's the problem with that? ...Except that my gorgeous love interest is the top protagonist of the novel. And me? Oh, I'm the background NPC mentioned at the beginning of the novel who got into a different school. We're childhood friends in name, but in reality I'm not even a passerby. I only exist in dialogue and phone calls. Hah. The blurb is in first person, but the main text isn't. A top who is a nobody x a bottom who is the top protagonist Content warning: The top is genuinely a total nobody. Theme: People have many choices, so I will become the only choice.