Poorman, Ark, Billionaire

Shiragaki Seiya, a high school student and the daughter of a mangaka, is anxious to become financially independent so as to relieve the burden on her single mother. One day while on the way to school, she has an encounter with "The Spirit of the Chest, Aurelia de Medici," and thereafter finds herself thrown headfirst into a no-holds-barred otherworldly battle revolving around money.