Top Billed Cast

1. 

   Lee Ji-hyun

   Romi (voice)

2. 

   Jo Kyoung-i

   Heartsping (voice)

3. 

   Choi Nak-yoon

   Heart King / Monster Truthping (voice)

4. 

   Yeo Min-jeong

   Belita / Girl (voice)

5. 

   Hong So-young

   Stella (voice)

6. 

   Hong Bum-ki

   Dr. Monziu / General Teenieping (voice)

7. 

   Kim Ha-yeong

   Marie (voice)

8. 

   Ryu Seung-gone

   Liam / Butler (voice)

9. 

   Cho Hyun-jung

   Truthping (voice)

10. 

    Kim Eun-ah

    Happying / Young Liam / Girl's Mom (voice)

11. 

    Jang Ye-na

    Lalaping / Maid / Stickping (voice)

12. 

    Um Sang-hyun

    Mr. Bus Stop / Freezeping (voice)