In his previous school, when Taebin was turned into a Dicer by Mooyoung, the two distributed Dice to a small number of schoolmates who became Taebin's first friends. This group was annihilated by Mooyoung when the first PVP stage was initiated by X, and it is then revealed that he had this in mind from the very beginning so he could challenge X for the S-Rank Die. Taebin was apparently the sole survivor and fled, but it was later found that Dawn survived, too.
That group discovered several pieces of information that later are relayed by Taebin to Dongtae.
The third Dicer. A short, energetic girl and Taebin's class student representative, she had short, dark hair and eyes and a practical attitude. She organised group meetings and her skill was Levitation. She was interested in Tarot cards, cooking and had a crush on Mooyoung.
She was devastated when Mooyoung showed his true colours. Dawn flew away to safety when he attacked the group, but distracted Mooyoung when he tried to kill Taebin. She was nearly killed instead, but survived with a severe throat injury. Dawn became embittered and blamed Taebin, and took on the persona of Hood to go after him in his new school.
It was Dawn who first hypothesised correctly that X is a person.
The fourth Dicer. A short, hyperactive, talkative kid, he spoke loud and thought of himself as setting the mood of the group. Mooyoung excepted, he completed the A-Rank quest first in the group, before Dawn did, and became a Cloaker. He had short, light brown hair and hazel eyes.
Oh-hyun had strong opinions, which included being against spreading the Dice to more people. He aspired at using Dice to build a brilliant future for himself. He also wasn't above using his skill to commit small misdemeanours like jumping the counter in underground stations.
The fifth Dicer and the third A-Ranker, with the power of Psychokinesis. He was tall, had dark grey hair around the head and black on top of it, and handsome looks. His hobby were sports and he had a crush on Dawn, which led him to be jealous of Mooyoung.
When Mooyoung began killing the group members, he tried to create a diversion by attacking him and instructed Dawn to escape. Mooyoung killed him by crushing his spinal cord.
The sixth Dicer and the fourth A-Ranker. She was a quiet girl who liked reading. She had long, dark hair and hazel eyes.
When she acquired the skill of Clairvoyance, Jihae put in action their plan of using a Mental Buff purchased from the store to enhance the power of the skill, and when putting it to the max, she made a number of interesting observations:
- When looking at a Dicer with maxed out Clairvoyance, she was able to see a strange landscape that could be either the sidereal space or sand.
- When looking at X's dialogue window in a smartphone, she was able to discern a small "opening" that led to a space where a giant cube was visible - possibly a dimensional space where X inhabits.
- When looking at Mooyoung right before he started his rampage, she was able to see multiple, superimposed stats boxes, but was unable to read their content. She understood them and told the others, in desperation, that they had to flee because Mooyoung had been planning to kill them from the very start and was a "different being".
Jihae was the first one to be killed by Mooyoung.
The seventh Dicer. A tall, bespectacled kid with short, dark brown, bowl-shaped hair, he had a stubborn personality and was academically strong with an interest in electronics.
Seyoon was the sixth one to become an A-Ranker, before Taebin did, and acquired Teleportation too. His accomplishment triggered the PVP Stage and Seyoon was the second to be killed by Mooyoung.