Nagaoka

Appears in Name Onna (The Licking Woman). Nagaoka is another victim of the Licking Woman, who meets Miku a few years after the Woman is sent to a psychiatric facility. She volunteers to sneak some potassium cyanide out of her university lab in order to poison the Woman.

[Spoiler] It is hinted that she is the titular "Licking Woman", since Miku finds the same glasses that Nagaoka wears, in the Woman's purse. Nagaoka is the one who encourages Miku to kill her using potassium cyanide that Nagaoka sneaks out of her university lab. [/Spoiler]