Sonia

Sonia is a former Harpoonist from the Floating City and a former member of the explorer team led by the late Jako Gusto, alongside her partner Gongtae Park, as well as a former resident of Port Oasis. She becomes an associate of the Bota and Rita Ma, as well as Kana, joining on their journey.

Sonia is an ally during the Genod and Return to Busan arcs, and briefly as an antagonist during the former.

Background
At some point in her life, Sonia enlisted to become a Harpoonist of the Floating City, though at the time of her departing from the settlement, she killed an unspecified number of sea monsters below a hundred.

One day Sonia met an explorer and former Harpoonist called Jako Gusto, alongside a fellow Harpoonist called Gongtae Park.

Personality
At its core, Sonia is a lighthearted and friendly woman. She has a notable flirtatious side, almost immediately getting attracted to Bota and playfully teasing him upon their first meeting. She also appears to have been quite boisterous and prideful, confidently showcasing her Harpoonist tattoo in spite of having killed less than a hundred sea monsters prior to her departure from the Floating City.

As a mercenary, Sonia originally only cared about profit and found idealism and optimism about the world foolish. Jako's personal quest to find a cure for the fish disease and his bond with her softened her view on the matter. After Jako's death, Sonia adopts his life mission as her own, hopeful that she can bring change to the world as her old friend and mentor wanted.

She is shown to be incredibly loyal to her closest friends, Jako and Gongtae, to the point of almost dying of suffocation due to grief upon finding the former's corpse. She was also immediately willing to search for Gongtae when he went missing. Most notably, upon encountering a mutated and devolved Jako, Sonia was incapable of striking him, and tearfully tried to stop Kana from executing him. Despite her flirtatious moments, she also appears to have grown seriously attached to Bota, caring for him after Genod's attack on Port Oasis.

Jako's demise somewhat darkened her personality, making her lose some of her humorous side and reflecting on her life.

Sonia also appears to get easily jealous. She forms a one-sided rivalry with Kana due to the latter's closer bond with Bota. This rivalry briefly evolved into hostility after Kana put Jako out of his misery, though the two later developed a somewhat warmer relationship upon leaving Port Oasis.