Complex sentence: Ayumi sang the evolution theme songs for "Digimon Adventure 02" ("Break Up! " and"Beat Hit! ") and the second evolution theme for"Digimon Frontier " ("The Last Element").
Split into simpler sentences: Ayumi sang the evolution theme songs for the "Digimon Adventure 02". After, he also sang the second evolution theme for the "Digimon Frontier" ("The Last Element").