Joi

Joi is one of the main heroes of Blade Runner 2049. She is a sentient hologram who is K's girlfriend. She is kind, gentle, compassionate and friendly. She offers K moral support and accompanies him on his quest to find the missing Replicant daughter. Before setting out to the ruins of Old Los Angeles, K downloads Joi into a mobile emitter that he carries with him. However, when K finds Deckard, Luv finds them. Luv, wanting to break K's spirit, realizes how much Joi means to K and thus smashes the mobile emitter, effectively killing Joi. When K manages to kill Luv, one could interpret this as K taking revenge for Luv killing Joi.