Felix

Anyone in this world can make a contract with a god-like entities. They can offer a wide variety of wishes on one condition. In payment, the payee must provide an attachment of sorts: memories, emotions, relationships, etc. Not many take them up on this offer, but the few who do are marked.

His family are well-known for their blue hair as a result of dealing with entities. Long time ago, an ancestor had requested an insane amount of backing from the entity. They had sacrificed a lot to it, including future generations, as payment. Each descendant of this person would suffer one great misfortune.

...

...