Complex sentence: Raina officially debuted with After School together with Nana in third generation and release second single "Because of You", which attained No.1 on the Gaon Digital Chart and won the "triple crown" on SBS "Inkigayo".
Split into simpler sentences: Raina officially debuted with After School together with Nana in the group's third generation. The group's second single, "Because of You", attained No.1 on the Gaon Digital Chart and won the "triple crown" on SBS' "Inkigayo".