Justin first appeared in episode 8, where Leopold's father, Harold, was sent a music video by his co-worker, John Edwards as a simple prank. However, this had the unfortunate side effect of giving Harold Bieber Fever. When, he returned home that afternoon and began playing Justin's music, Leopold is driven berserk along with Leonard, culminating in them destroying Harold's music player... only for Harold to retaliate by beating the two brothers senseless.
In Episode 11, Leopold manages to find some Bieber fail videos and sends them to Harold, revealing his true colors as a failure, effectively "curing" him of his Bieber Fever.
In Episode 20, Leopold had had enough of Justin and goes off to assassinate him. However, he would eventually team up with Adolf Hitler, and eventually succeed in "killing" Justin with a WTF Bomb disguised as a water bottle.
In the first movie, Invasion of the Bieber Fever Army, he was revealed to have survived and was rebuilt into a cyborg, and with help from Rebecca Black, Rick Astley, Mr. Trololol, and Tunak Tunak Tun, founded the Bieber Fever Army, or the BFA for short, and tried to take over the world. Leopold, Harold and Hitler teamed up and fought back, successfully thwarting the BFA's plan and defeating Justin.
In episode 36, when Leopold went to a new school, the Principal, Suckson Dikshitt, who unbeknowns to Leopold was a servant of Justin, trapped Leopold and kidnapped him. On the way to Justin's lair, TheShaneDawsonFan noticed Leopold being carried by Dikshitt, and he went to find and get help from Fegelein. After rescuing Leopold, they along with several of TheShaneDawsonFan's friends on YouTube succeed in helping Leopold defeat him once again.
In episode 47, he is revealed to be Leopold's new teacher as soon as the school was reopened. In episode 49, however, Leopold uncovers a plot to take over the world once again and tried to stop him but was defeated by Justin who had donned the Mark 1 Prototype Mechadroid suit. In episode 50, after getting help from TheKewlOne96, he successfully defeated Justin and forced him to retreat.
Justin reappeared in the in the later half of the second movie, Dangers of the Internet, where he has been repaired and inserted into a completed version of the Mechadroid suit he previously utilized. Justin was finally defeated and permanently destroyed, making this his final appearance in TheKewlOne96's series.
|1st Time||Movie 1||ARK Music Factory||300|
|2nd Time||Episode 36-38||Justin Bieber's Basement||300 + 600 + 900|
|3rd Time||Episode 49||Leopold's School||500|
|4th Time||Episode 50||Leopold's School||500|
|5th Time||Movie 2||Cyber||1000|
In episode 55, Leopold once wrote an essay regarding the worst singer ever. He called Justin "Justin Buttfucker" and eventually get punished.
It's known that Mrs. Sukscox loves Justin's music. She was unhappy when he saw Leopold's essay.
Justin Bieber only appears as a SPOILER alert like Donald Trump.
Justin Bieber debuts on AGK in Europe as he plans to brainwash all girls in the world by his hypnotizing machine weapon instead of listening his song because it's copyright and he kills anyone who opposed to him with his hi-tech weapon. after the "World Tour Saga" episodes, Nova replaced him as the main antagonist.
- Chris Wong plays kill Justin Bieber game (in real life) and he dies in episode 161.
- In Margaretka4356's series, Aerial Slikk gets Bieber Fever, and Xenia likes to listen to his music, and Leopold's classmates Sarah and Sandra love him.
- He was declared a persona non grata by the government of the Philippines for posting something on Instagram that was deemed racist.
- As seen in episode 11(TheKewlOne96) It showed that Justin Bieber doesn't know what German means, which explains how Harold started to hate him.