I told the moon about you

Soulmates are rare but they exist. But sometimes souls depart from each other. Sometimes souls have to be born in the world to repent for a few sins they've committed knowingly or unknowingly in a past life. Their soulmates can decide whether they want to protect half of their souls from any harm that come their way from a different celestial plane as their guardian angel or being born with them, taking up the challenge to find them in the vast universe and share their pain with them. Tsukishima chose the first option.Or,A Soulmate AU, where Yamaguchi runs on honey tea, soulmate fanfictions and suicidal thoughts and Tsukishima is forced to come down to earth to save Yamaguchi from the biggest harm that comes to the star-cheeked boy's way. Himself.