Something strange happened at Sakura's school. Every night, singing would come from the music room.Sakura was very scared when she heard this story.Xiao Ke and Tomoyo suspected that the Clow card was causing trouble and asked Sakura to conquer it at night.Sakura hesitated and finally agreed.When they came to the classroom, they found that this was a Gokuro card. It was learning how to sing. Since it was always bad at singing, it had to be practiced every night.Tomoyo used singing to lure it out, and Sakura subdued it.