Jun Hosoe is a character from the second round of the Liar Game tournament. She is a woman who appears to be in her mid-twenties and works as an office lady, or OL, for a real estate company. Her typical attire reflects her corporate occupation, consisting of a blouse and a smart skirt.

Hosoe has a nervous and somewhat indecisive personality, often worrying about even the smallest details. It is suggested that she may lead a lonely life, as she spends a significant amount of her free time at host clubs. This habit became an addiction, leading her to accumulate a large amount of debt after being pressured by a persistent host. Her financial desperation was such that she considered selling herself to obtain the money but could not gather the courage to do so.

Within the story, Hosoe is one of the six contestants who form an alliance with the protagonist, Kanzaki Nao. She is selected by Nao for this team because she is female, a criterion used to avoid including a male player designated as Mr. X who is suspected of working for the game organizers. Along with another team member, Matsubara Fumio, Hosoe helps draw up the contract that formalizes their alliance. During the initial vote of the Minority Rule game, she votes No and is eliminated from that round. Her involvement in the Liar Game concludes when she is able to drop out of the tournament entirely, thanks to a share of the prize money won by her ally, Akiyama Shinichi.