Chocolategifts given by women to men on Valentine's Day out of social obligation rather than romantic interest. Unlike honmei choco, which is given to romantic partners, obligation chocolate is given to male co-workers, bosses, and acquaintances out of appreciation and politeness.
Men generally reciprocate by giving women gifts on White Day, which is celebrated on March 14.
A common trope is for tsundere characters to claim it's just an obligation chocolate.
