Complex sentence: It is a six-part series of films in Akiyoshi Hongo's "Digimon" franchise, serving as a direct sequel to the first two television series, "Digimon Adventure" and "Digimon Adventure 02", and celebrates the anime franchise's 15th anniversary.
Split into simpler sentences: It is a six-part series of films in Akiyoshi Hongo's "Digimon" franchise. It serves as a direct sequel to the first two television series, "Digimon Adventure" and "Digimon Adventure 02", and celebrates the anime franchise's 15th anniversary.