Sinister Heartbreak is a shadowy blob of a demoness with fin-like horns and battered-up wings. She possesses a massive belly, huge hips, and a large pair of breasts that spill out of her crimson red smiley-face bikini top. She also has two chained cuffs latched on to both of her wrists, and a red bowtie and a shattered heart on the top of her head. Despite her appearance, she is very nerdy about Japanese media, and is very quirky around other people. Her favorite food is cheeseburgers.