Au idea becuz I usually use discord for this stuff but wattpad is more available to me on chrome:
There's a rumor or whatever where they say "if you let go of a balloon, it'll find it's way to your soulmate." Shuichi (becuz I am saiouma enthusiast) doesn't believe this whatsoever, but tries it anyway because his family is encouraging him to. So, he ties a paper talking about himself onto the string thingy of the balloon. He lets it go, having his hopes as high as the ground. The balloon flies on for a few weeks, and Shuichi already somewhat forgot about it. It found it's way to Kokichi, who feels indifferent about the little rumor. His friends and him look and read the paper together, and while his friends are excited to find Shuichi, Kokichi can't care less about it.
Fast forward a few years later, Shuichi and Kokichi cross paths. Maybe they're in the same school, maybe they bumped into each other while at a store, idfc. They hang out, find each other interesting, but *something* about Shuichi's name feels familiar to Kokichi, but they can't seem to put their finger on it. "It doesn't matter though," he constantly tells himself. Stuff happens, things click in place, and Kokichi's like
"Wait you sent me a balloon with your address on it? Isn't that, like, really dangerous??"
And Shuichi's just, "I was 11 at the time aight? I didn't know any better, I just cared about the newest video game."
And then they move together and adopt kids (probably the WoH idrc) and live happily ever after