Hello and thank you for your patience. Per the livestreamed drawing, the villager saved by Hijikata and Rei is:

Old Lady Piña
Yes, her name does mean Pineapple. A gleeful old coot, she has trouble walking and got caught by the ICE. You, her savior, definitely have her joking and giving you a hard time, but she also hands over some of the bracelets she had gotten from her grand daughter. They will protect you from the effects of a single potion passively, so you're protected whether you know you're consuming it or not. One for you and one for someone important to you, each.