Bustard

Not much is known about Great Bustard, mainly only the fact that he is the leader of the Yuna Band and feared by most (if not all) of its members.

At first, it seemed like Bustard was the man with the black fur vest. However, after Ch. 35, it seems more likely that he is the red haired older man wearing a gray hat.

The man wearing the black fur best appears to be the one that was purposefully and accidentally murdered by members of the Yuna Band. At one point Bustard contacted the Park twins as well as Shung. He told the twins to keep someone occupied for a few hours on the phone. Shung was, at the time, working at his parent's store. Receiving a call, he was told about the man outside on his phone (possibly talking to the twins). The man on the phone said that he was running late to meet him, and asked Shung if he could let him inside. Shung did so, letting the man sit on a couch in front of a brazier to warm up. Not long after, Crow (Rin) entered the store and poured something into the fireplace. Without noticing, Shung looked over some moments later to where the man had been sitting, and didn't see him from over the counter. Shung went over to check, and found the man on the floor bleeding from his mouth and eyes.

The man died due to hydrochloric acid gas (refer to Ch. 25). Yet strangely, the same man is seen in Ch. 03 watching Yuna and Onyu from a distance. According to the words from the Park twins and Shung, this event happened sometime after they graduated from middle school.

In chapter 35, after Shung sends a photo to the Yuna Band chat of him and Yuna kissing in a way to instigate the remaining members and draw them out. Almost immediately after, a van pulls up to where they are, and the red-haired man attempts to kidnap Yuna. Cuckoo is also in the van with him, but seems conflicted about the turn of events. Shung and Onyu try to protect her and prevent the kidnapping, but Shung gets stabbed in the process. As Cuckoo holds onto Yuna in the van, Great Bustard angrily grabs Cuckoo's hair, to which Cuckoo responds by slicing Bustard's hand.

Cuckoo and Yuna somehow end up outside the van. Yuna immediately wants to go to help Shung, but Cuckoo grabs onto her and tells her she can't go. Bustard exits the van and confronts Cuckoo, and Onyu quickly comes to protect Yuna, stepping on Cuckoo's shoulder in the process and cracking some of his bones. One of Cuckoo's friends from school appears at the scene with a bat, and tells Bustard to quietly leave, which he does. Cuckoo's friend then approaches Onyu and Yuna, sternly telling them that his friend us hurt and they will accompany him to the hospital. Ch. 36 ends with one of Cuckoo's other friends saying he heart isn't beating.

Bustard is the version of Onyu that travels back in time when he was a child. He is the one who becomes friends with Cuckoo and stalk Yuna. He created the Yuna Band to likely keep people away from her, because he wants her to himself. Although he originally had blond hair, he dyed it early on to red, similar to Cuckoo's hair color. He is responsible for the death of Ji-Hyun Kang and Cuckoo's aunt.