[yes, I know that's ariana grande but for this story it isn't ok thx]
Luna Fujisaki-Clifford always wanted to study music on a firsthand, so when she got an offer to be an assistant manager for a band, she almost fainted. Unfortunately, she got set with her brothers band, 5 Seconds Of Summer, which could be worse. Well, in her mind, it couldn't. After all of the "don't touch my sister" "pLEASE DON'T HOOK UP WITH ONE OF MY FRIENDS" lectures, Luna has a shit ton of work and it's everything but easy with her brother, Michael, annoying her to death, Ashton and Calum fucking around, and Luke being anything but normal. How will she survive?
...And will she break one of her brother's rules for the best, or the worst?
Transmigrated into DxD World-Kuoh Town, Hibari Kyoya. an average student, spent 18 agonizing years in the world fully aware of the dangers, knowing he is utterly powerless in a world of gods and monsters, Until...
[Ding! Sign-In System loading... 20%... 50%... 80%... 100%.]
Destiny, it seems.. has a cruel sense of humor. A [Sign-In System], long overdue, finally bursts to life within him, offering a chance at survival, a chance at power...
[Ding! Congratulations! You have received the Rainbow-Grade Gift Bag!]
...
He then started completing System's tasks, accumulating even greater rewards.
[Ding! Task completed. Reward: Perfect Rumble-Rumble Fruit (Weakness to water Removed).]
[Ding! Task completed. Congratulations to the host for obtaining the Flying Thunder God Technique!]