A piece of urban folklore: If you see another you, identical in every way, it's your doppelganger, and it's about to replace you. Be careful!
A monster that's not human, yet has your appearance and memories, appears out of nowhere and may do who knows what.
Sometimes, even your friends and family can't tell that “he” is there!
Oikawa decides to catch that doppelganger! He goes to his friend and pours out all his grievances.
“He ate all the cookies in my house. And my sister blamed me?!”
“He rummages through my things, takes my allowance, and wears my clothes!”
“He even threw out all my homework!”
“...Iwa-chan?”
Iwaizumi rubbed his face in exasperation and said calmly, “How am I supposed to know if you're Oikawa or that doppelganger?”
“?!!”
Oikawa flew into a rage, then stole Iwaizumi's cookies too.
Iwaizumi: “...Too?”
*
As a doppelganger, Kagami had been free from the moment he was born.
He could read books without reading them himself, skip doing his own homework, take ready-made friends, taste meals ahead of time, and tear up girls' love letters.
The original got mad? Must be jealous, right?
On the desk was a pink envelope containing a letter in identical handwriting:
[Hello,
I heard you've been looking for me everywhere. There's no need.
After all, sooner or later, we'll see each other (smile).]
On the back of the paper:
[I and myself are one.]
[I kill myself, and only I can.]
[I love myself, so embrace me.]
After reading the letter, the original blushed (smile).
He was too furious to catch me (smile).
“When you see me, either kill me or love me.”
“I” and “I” aren't the same.
#
Nobody knew when he first appeared. Maybe in his first year of high school, maybe in his third year of middle school, maybe even earlier.
At first, Iwaizumi couldn't tell them apart, because they looked so much alike.
Later
“You want to interview Oikawa? There he is, the one hitting the volleyball with a loud thwack.”
“Iwa-chan!!!” Oikawa shouted angrily.
“That's me.” Kagami tossed the ball aside, his gentle smile fixed in place.
[Reader's Guide]
1. OOC warning.
2. Two setters. This is about a mirror who competes and fights for everything.
3. A pseudo-selfcest, switch romance with a somewhat unscientific worldbuilding.
4. A slice-of-life story about two immature idiots, more or less.
5. The blurb may change. The version at the time of posting will be final.
Theme: The future holds endless possibilities. Move toward the direction you yearn for.