Whether you use the physical box set or a digital , the method remains the same: Tadoku (Extensive Reading).
Volume 1 usually includes a simplified version of a classic folktale, such as Kasajizō or Urashima Tarō . These stories are the cultural bedrock of Japan. Reading them in Level 0 is an act of cultural decoding. The language is simplified, but the narrative beats remain. The learner realizes, "I am reading a real Japanese story." It is an immense psychological boost. Japanese Graded Readers Level 0 - Vol. 1 Pdf