Karen Konohara, a 23-year-old nurse in the obstetrics and gynecology department, stands 167 cm tall and weighs 52 kg, with body measurements of 86-54-86 cm, blue hair, blue eyes, and blood type A. She attended nursing school alongside colleague Ai, forming a close friendship where she exhibits an older-sister demeanor. Karen demonstrates greater professional competence than Ai. Typically stern and intimidating, she frequently directs angry outbursts at staff, yet softens exclusively for Ai, revealing a caring side. Diagnosed with germaphobia, she compulsively disinfects hands after touching objects or surfaces and changes gloves immediately after physical contact—especially with men—often discarding them post-handshake. This germaphobia selectively vanishes around Ai and hospital director Riru. Her speech carries a rough, brusque quality from a strict upbringing; she secretly attempts refinement but habitually reverts with close colleagues. Despite touch aversion and brusque distancing tactics, Karen harbors intense hidden feelings for colleague Mana Kazama, placing complete trust in her and experiencing secret sexual desires that manifest in nightly masturbation focused on Mana. She masks this beneath her stern, reclusive exterior. As Mana's mentor, Karen frequently admonishes her for tardiness or errors, reflecting both high standards and a connection transcending her usual harshness.