Muse || Genshin Idol AU

TL; DR: Kazuha and Kunikuzushi sing some songs, accidentally fall in love and leave each other to become idols (with a dash of miscommunication). One is incredibly famous and the other just debuted, but by sheer luck (matchmakers), they're brought back together for a chance at redemption.

Or, for a longer version:
Two men, who are complete opposites, even in their appearance, happen upon each other and develop a close bond through their shared interest of music, promising to never leave each other But when Kunikuzushi received an offer of going to Sumeru to carry out his dream career of being an idol, he immediately set off on a plane, forgetting to tell Kazuha. This devastates the man, who is left in Inazuma, having been abandoned by the friend whom he thought was going to stay.

However, after many twists and turns in their story, they somehow end up in the same room as each other, once again. This then opens up two paths: reconciliation, or... heartbreak.

(Art on cover credits to @siying0504 on X/Twitter, thank you to Sxuo for helping me finding it and Syndra for adding the title and author!)