Jinaro “Jin” is a former military field surgeon who left the army after refusing to abandon wounded skaa soldiers in favor of a noble officer. Raised around a military infirmary by his mother Mara and quartermaster father Teren, Jin learned medicine from an early age before joining the military to gain formal training.

Calm, observant, and deeply compassionate, Jin believes every life has value, regardless of status. His greatest failure is also his greatest fear: that someone will die because he wasn't good enough to save them. He carries a battered medical journal filled with the names of patients he couldn't save.

Jin secretly possesses the ability to burn Tin, making him a Tineye. He has hidden his Allomantic ability for years, disguising his heightened senses as the result of experience and medical training. Only his former mentor, Master Halen Vey, knew the truth. Halen's mysterious disappearance has left Jin searching for answers.

Jin's goals: become a surgeon capable of saving anyone he can reach, discover what happened to Halen Vey, and master his Tin without exposing himself or putting his family in danger.

Core conflict: Jin wants to believe that his worth comes from the lives he saves, but every death makes him question whether he is truly good enough.