Lee Ji-hyun
Romi (voice)
Lee Ji-hyun
Romi (voice)
Jo Kyoung-i
Heartsping (voice)
Choi Nak-yoon
Heart King / Monster Truthping (voice)
Yeo Min-jeong
Belita / Girl (voice)
Hong So-young
Stella (voice)
Hong Bum-ki
Dr. Monziu / General Teenieping (voice)
Kim Ha-yeong
Marie (voice)
Ryu Seung-gone
Liam / Butler (voice)
Cho Hyun-jung
Truthping (voice)
Kim Eun-ah
Happying / Young Liam / Girl's Mom (voice)
Jang Ye-na
Lalaping / Maid / Stickping (voice)
Um Sang-hyun
Mr. Bus Stop / Freezeping (voice)
Kim Su-hoon
Director
Min Seul-ki
Producer
Song Mi-seon
Producer
Shin Hyeon-deok
Producer
Kim Su-hoon
Executive Producer
Jo Seong-hee
Sound
WINTER
Theme Song Performance
Kim Dae-yeol
VFX Supervisor
Ryota Yamaguchi
Original Story
Kim Young-jin
Animation Director
Naruhisa Arakawa
Writer
Kim Tae-ho
Music
Kang Byeong-chae
Producer
Jo Yeong-gwang
Storyboard
Im Ji-eun
Production Design
Kim Yu-jin
Production Design
Seo Bo-guk
Art Direction