sanji

Theres 2 districts, Luna and one that starts with an F but idk how to spell it. Main guy was hired by leader of F to kill leader of Luna and take some important documents but they end up falling in love. Luna leader doesn't know that mc is hired by leader of F and mc is conflicted because if he doesn't finish the mission his sick brother won't receive treatment and die. Most recent chapters are about Luna leaders past with F leader

Sorry actually the guy isn't the Luna leader he's the heir. His older sister is currently the Luna leader

Does the guy he is supposed to kill already find out or not yet? Also I remember there being hints of a side couple , did it happen ?!

He doesn't know yet. The side couple is between the Luna leaders childhood friend and a guy that works at a pub. They do actually get together but they're only in a couple of chapters

Sorry I got some things wrong so I'm gonna retype my summary with names and everything.

There are many districts but Luna and Formicarium are the most influential. They're fighting over property of a territory called Liveta and Luna has the upper hand. Victor, younger brother of the Luna leader is living in Liveta as a sort of unoffical leader. To legally live in a district you need a district tattoo as proof of citizenship otherwise you're a "gray". The mc, Yohan, is a gray so he doesn't have access to certain things like medical care, education, etc. Yohans brother (also a gray) is really sick and needs treatment ASAP. To pay for the treatment Yohan agrees to spy on Victor and retrieve a list of all the district leaders that support Luna. As a cover he's hired as Victor's bodyguard. Overtime they start falling for each other and so Yohan basically has to choose Victor or his brother. Victor is unaware of Yohans true objective.

The side couple is between Victor's childhood friend, Van and a pub worker, Ian. Ian's boss is Van's grandfather.