Sandy

Sandy is the main antagonist of No Lunch Break webcomic. She works at customer service in Teiai Industries. Sandy initially appears as a sweet and friendly young woman, but as the story progresses, she turns out to be a highly manipulative, rude and vengeful co-worker who is out to get revenge on Sydney and her friends and ruin their social lives. Sandy also has a bipolar and multiple personality disorder.

Personality
Sandy starts out appearing as a sweet, friendly person who likes to giving support and advice to Sydney and Tina and enjoys hanging out with them and having a meal together.

However, this was merely a facade to hide her true nature as a manipulative, vengeful and embittered person.