Lore

Sen was born in Limsa Lominsa to a Raen Au Ra couple who had moved from Othard a few years back. Her mother had joined a pirate gang called the Red Serpents, and ended up falling in love and having a secret relationship with the boss of the pirate group. Eventually the secret became public and Sen's father was furious and something snapped in his head, and he ended up killing Sen's mother and himself in one go. Sen was around 10 years old when this happened. The Red Serpent's boss was heartbroken and ended up adopting Sen after the incident, and lovingly raised Sen to be the next boss of the group once she's gone. She loved Sen very much and she resembled her mother a lot.

Some years later Sen's adoption mother died in a fight where another pirate group invaded their base, and many others died during that as well. Sen was devastated after losing another close one to her, but gathered herself for the Red Serpents and became the new boss and also became kind of like a mother figure to all of the remaining members. Sen now handles all of the Red Serpents' paperwork and runs the tavern that belongs to them.

A few years later, another mercenary/pirate group called the Phantom Blood requested an alliance with the Red Serpents, and Sen accepted, since at the time it seemed beneficial for both of the groups. Unfortunately, the Phantom Blood is above the Red Serpents, and they definitely act like it as well, their commander making them do all kinds of terrible jobs and treating the group like scum, except Sen.

Sen befriends the commander, Minerva, after a very long rocky path, and eventually there starts to be some deeper feelings as well, and soon enough she has fallen in love with her.