Chiitan gained popularity through its unusual YouTube videos and social media posts in which it performed various clumsy or violent stunts.

In January 2019, complaints about the controversial nature of Chiitan's videos and social media posts led Susaki officials to reject its association with the mascot.

The episode praised Chiitan's antics but led its host, John Oliver, to create "Chiijohn", a replacement mascot-friend for Shinjo-kun.

In 2013, the city of Susaki, Kochi Prefecture unveiled an official mascot called Shinjo-kun (しんじょう君), an extinct Japanese river otter wearing a nabeyaki (hot pot) ramen dish for a hat.

[1] Some of Chiitan's videos included it hitting a punching bag with a baseball bat, jumping into metal boxes, flipping a car, twirling a motorized weed cutter around its head,[5] falling off a pogo stick, failing at bowling, and falling off a bike while trying to fire a bow and arrow.

[8] In one video, captioned "Chiitan is going to visit your house", the mascot takes a baseball bat from a locker, stuffs it into its costume, and walks offscreen.

One post, in which Chiitan carries a miniature baseball bat and Shinjo-kun is dressed as a gangster, is captioned: "We're the bosses, don't mess with us or we'll commit otterocities.

[12] Chiitan's social media posts were controversial, and by January 2019 the government of Susaki had received over 100 complaints from citizens who objected to the city's association with the mascot.

In addition to preventing its officials and official mascot from appearing with Chiitan, the city's mayor, Kosaku Kusunose, requested that Chiitan "suspend activities" in February, claiming that the mascot was guilty of violating a copyright on the character's image owned by the city[5] and accusing the company managing the character of profiting off of it.

[5] After losing its association with Susaki, Chiitan was the topic of an episode of John Oliver's HBO program, Last Week Tonight.

In the episode John Oliver explained how the mascot came to be, and praised its strange and humorous videos as "amazing", "a work of art", and "virtuosic".

Oliver then created and sent his own mascot, "Chiijohn", "a 41-year-old nearsighted English fairy baby", to Susaki in order to befriend Shinjo-kun.

[14] Despite the claims of the company managing Chiitan that it produced only "healthy" content that was neither prejudicial nor malicious, others suggested that the "anarchic" nature of the mascot's videos was what led to its Twitter accounts' suspension.

[16] Twitter refused to make a statement on the suspensions, saying it was company policy not to comment on private accounts due to security and privacy concerns.