Utashima sports messy, short green hair with bangs swept to the right and wears rectangular half-rim glasses purely for appearance, as they are non-prescription. He possesses an average height and build, dressing stylishly to cultivate his image. He embraces a carefree and easy-going personality, considering this trait a positive quality. Utashima is easily swayed by cute appearances, readily agreeing to Ryuji Ayukawa's request to speak privately with Yatora Yaguchi. His outwardly flashy demeanor initially attracts younger girls, but he remains unpopular with peers his own age, who often find him annoying and tell him to "get it together." Yatora Yaguchi observes that while Utashima appears attractive to strangers, his appeal fades significantly for those who know him well, suggesting he would be more attractive if silent. Academically unmotivated, Utashima does not apply himself. He takes the National Center Test for University Admissions as a formality, fully aware he will fail. After failing his entrance exams, he briefly considers becoming a ronin but abandons the plan upon realizing he lacks any genuine desire to attend university. With no specific dreams or ambitions, he begins working part-time as a barista at "STAR FRONT COFFEE," wearing an apron during shifts. Socially, Utashima plays guitar in a cover band called "The Matieres." His band involvement and stylish look maintain his popularity with younger female students, though not with girls in his own year. By high school graduation, even his underclassmen popularity wanes, as no one asks him for a uniform button. Utashima belongs to Yatora Yaguchi's close high school friend group, including Koigakubo and Sumida. They frequently socialize by watching football games, smoking, and drinking together. While supportive, Utashima's relationship with the group initially feels shallow due to Yatora suppressing his true feelings. Eventually, the friends recognize Yatora's struggles and support his decision to pursue art. Koigakubo shows particular insight into Yatora's emotional state, offering advice when Yatora opens up. No significant character development or changes in Utashima's circumstances are documented beyond his post-graduation employment and the evolution of his friendships. His role remains consistent as a supporting figure within Yatora's social circle, characterized by his laid-back approach to life and lack of long-term aspirations.