Ring in joy with I'm so Free! by Miki Hoshii, Azusa Miura, and Takane Shijou from IDOLM@STER, IDOLM@STER2. This pop anthem, sung by Akiko Hasegawa, Chiaki Takahashi, and Yumi Hara, is perfect for notifications. Feels engaging and energetic, radiating freedom and happiness.