The second season of MARRIAGETOXIN continues the story of Hikaru Gero, heir to the Gero Family of Poison Masters, one of the Five Great Families that wield the most feared power in the underworld. The first season set him against his family head's demand that his sister produce an heir, and brought him into contact with Mei Kinosaki, a skilled marriage swindler he was assigned to target. The new season mixes action and comedy with drama and romance.