Kang Maru is Muyeong's friend as well as his only connection to the chachaoong world at the start of the story. Maru helps him gather information about other chachaoongs as a way to pay a previous debt.
Maru appears as a young man in his early twenties. He has short, somewhat shaggy blond hair and amber eyes, and is always seen wearing a black shirt with red sleeve garters, a red tie, and red trousers.
Maru has an easygoing, cautious personality, and dislikes fighting. He is very fond of women and can be perverted at times (such as insisting on wearing sunglasses so no one can see him eyeing up potential girlfriends). However, he does not seem to have any luck with women, since he has been single his entire life. He is a devoted friend of Muyeong almost to the point of being a follower or lackey.
Maru's primary ability so far is enhanced hearing, similar to that of Muyeong's extreme visual acuity. Not only can Maru listen in on conversations happening in buildings some distance from where he is, but he can hear things such as irregularities in the heartbeats of people passing by him on a crowded street.
When summoning weapons, he specializes in firearms rather than blades; his guns (though small) have far more power than a normal weapon of the same size as well as the ability to shoot fire.
- Shin Muyeong - Maru's only significant relationship to date. The two of them are good enough friends to rely on each other for favors and protection. Maru refers to Muyeong as "Hyung-nim". Muyeong treats Maru much like a younger brother, including forcing him to study for and achieve his GED.
- Sora - They appear to know each other fairly well, and are on friendly terms with one another.
Nothing is known of Maru's past prior to the start of the story other than that he wandered around until he "was caught" by Muyeong, and became his only connection to the rest of the chachaoong community for a while.
Part 1 Season 1Edit
Maru is sitting on a park bench when he receives a call from Muyeong, surprised that his friend has returned earlier than expected, but Muyeong simply asks that they meet up. At a cafe, Maru admits that he is aware that there is a new king, not from hearing the news from anyone but because the knowledge was suddenly in his head. When Muyeong reveals that the new king is Jin, Maru becomes excited for him because of their existing association. Muyeong next asks about the Imae Tal, and Maru replies that he was the one Tal who never took off his mask, that he disappeared two years ago, and that one rumor is that Imae was killed by Bigak. Muyeong nexts asks Maru to gather information from the other chachaoongs, since many of them are opposed to Jin. Muyeong also has another favor to ask... Before parting ways, Maru asks Muyeong to avoid getting involved with Bigak.
Later on, Maru is caught eavesdropping on a group of chachaoongs inside a nearby apartment, and one of them comes out to confront him. When he attacks, Maru defends himself with a pair of guns he materializes before retreating.
Maru calls Muyeong and reports that he found the type of people he wanted him to follow, but was chased away before he could hear all the important info, only that the group plans to attack when Jin and Imae are not together. Muyeong checks to make sure his friend is okay before he tells him to continue gathering intel.