Doctor Usanagi is a member of the Followers of the Apocalypse. She received medical training at the Angel's Boneyard Medical University in the NCR. She has extensive medical knowledge and skills, and uses it to improve the lives of the Freesiders and NCR squatters, and also seems to be the person best skilled in dealing with psychological trauma. Doctor Usanagi runs the New Vegas medical clinic, located east of the Crimson Caravan Company. She speaks with a kind tone, and will help with any medical issues the Courier may have, for a price.
If the Courier has Intelligence of 3 or below, Usanagi will give them a discount on the Intelligence Implant out of pity. This relates to unmodified base S.P.E.C.I.A.L. Intelligence, so temporarily lowering Intelligence by chems does not count, but gives the special dialogue options ("You sell plants?") with no other effect.
Caps paid for implants will not go into Doctor Usanagi's inventory for bartering purposes.
If the player requests an implant for a S.P.E.C.I.A.L. attribute that is already at 10, Usanagi has unique dialogue marveling at the player's capabilities:
Strength: "You're already the strongest person I've ever met. The implant won't do anything more for you. "
Perception: "Your eyesight would make a hawk jealous. The Optic Enhancer implant won't do anything more for you. "
Endurance: "Your cardiovascular system is practically super-human. The Nociception Regulator won't boost it any further. "
Charisma: "You're already quite charming. The Empathy Synthesizer would just be a waste of caps, I'm afraid. "
Intelligence: "Your higher brain functions are off the charts. The implant won't help at all – sorry. "
Agility: "Your reaction times are already so fast it's a wonder you can't catch bullets. The Reflex Booster can't make you any faster. "
Luck: "Huh. I've never seen a coin toss go someone's way that many times. You certainly don't need the help of a Probability Calculator implant. In fact, you ought to be on the Strip cleaning out the casinos. "
"We believe that technology for basic necessities, like food, water, and medicine, should be shared, not hoarded. We're also strongly in favor of proper education. I've come across more than a few "doctors" whose techniques came out of the back of a magazine."
pcxbox360 Although Usanagi will ask for donations to the Followers of Apocalypse, a buggy script checks her inventory instead of the player's for the required caps, thus preventing donations from being made. [verified]
pcxbox360ps3 Sometimes the dialogue option to ask Doctor Usanagi to heal you will disappear entirely, rendering it impossible to regain health or heal crippled limbs by her. [verified]
pcps3 Rarely, she may sink into the floor, only surfacing when you ask her certain things (you can talk to her while she is under) such as asking to be healed or browsing her inventory, and after exiting dialogue she will sink into the floor. [verified]
pcxbox360ps3 Though Doctor Usanagi's dialog option to cure the Courier's addictions is set up to remove 50 caps in exchange for services, it does not check to ensure the player has at least 50 caps before becoming visible. This means Doctor Usanagi can cure the player's addictions even if they do not have enough caps, though at the cost of what few caps - if any - the player has. [verified]
pcxbox360 Sometimes Doctor Usanagi's dialogue option to raise Intelligence will not show up. This may be resolved by ending the conversation and taking an Intelligence draining item such as whiskey or beer, then enter dialogue again with Doctor Usanagi, when entering the "I want to buy an implant." dialogue the Intelligence option will be back. [verified]