The song is Oyasumi no Uta (おやすみのうた).
The full song (6 min & 24 sec), between 3:21 to 4:07, contains some dialogue between 3 girls and a ghost (おばけ/obake).
I've tried searching for lyrics containing this dialogue, but all just skip over this particular part.
All I ask is for someone to convert this dialogue into written Japanese form.
Please help me with this cute song.