A new and distinct cultivar of Chrysanthemum plant named ‘Fichrymerchepu’, characterized by its upright to outwardly spreading and uniformly and broadly mounded plant habit; moderately vigorous growth habit; freely branching habit; dense and full plant form; uniform and freely flowering habit; medium-sized decorative-type inflorescences with dark red purple-colored ray florets; mid-season flowering habit, grown under natural season conditions, plants begin flowering in early to mid-September in the United Kingdom; and good garden performance.
