This study aims to analyze the innovation of Japanese manju cake (Manju/饅頭) using local purple sweet potato (Ipomoea batatas L.) as the primary filling ingredient to produce a product called Futago Manju. The research employed a Research and Development (R&D) method. Three sugar formulation treatments were applied to the purple sweet potato paste in order to determine the best formulation: F1 (20% sugar), F2 (30% sugar), and F3 (50% sugar). These treatments aimed to examine the influence of sugar concentration on the physical, chemical, and sensory properties of the product. The study was conducted at the Culinary Laboratory of the Department of Family Welfare Education, Faculty of Engineering, Universitas Negeri Manado (UNIMA) over a period of three months. Nutritional analysis was performed by submitting samples to the Industrial Standardization and Service Center (BSJI) Manado, with laboratory testing conducted over two weeks. Based on the BSJI Manado results: F1 showed moisture content of 34.18%, total sugar 17.03%, total fat 29.78%, and protein 4.11%; F2 showed moisture content of 33.32%, total sugar 18.40%, total fat 37.92%, and protein 4.11%; F3 showed moisture content of 32.40%, total sugar 22.21%, total fat 39.61%, and protein 4.00%. Organoleptic testing involved 12 panelists comprising 8 students, 2 PKK lecturers from the Faculty of Engineering UNIMA, 1 Indonesian community member, and 1 Japanese community member. Sensory evaluations covering taste, color, aroma, and texture yielded mean preference scores of F1 = 3.74, F2 = 3.84, and F3 = 3.98. Formulation F3 with 50% sugar achieved the highest panelist preference score and is established as the standard formulation for the Futago Manju innovation product.