From the wealthy family of the Hiramatsu, Erika is one of the richest and most influential people in Tokyo. Like her social media persona, she's sweet, charismatic, and enthusiastic. Before the event of the story, she first met Isshin at the gym. Eventually, the two became a couple and only dated for a few months. The relationship between the two is more mutual as it is touching. They trust and support one another whether it's big or small. Much like the other supporting cast, Erika is aware that Isshin is a Raiju Modifier and is willing to be a major help by convincing her family to be the financial support for the Raiju Clan.