Jumin disregards others' opinions of him, so he lives his life how he thinks is right. He is a workaholic, which is shown through how he works Jaehee Kang to the bone however, Jaehee states that Jumin's workload is ever greater than hers.
He views situations objectively, and wants others to be like him.
He is often surrounded by rumors concerning his sexuality because of his complete lack of interest in women, leading the press and other members of the RFA to tease him for possibly being gay. He also enjoys teasing Zen about his cat allergy in the chat room. In fact, in his own way, his general cadence will give off that of a child's, often being innocently unaware of many things such as free bottles of soda given with takeaways. Despite this, he is interested in young slang and loves to talk about cats, especially his own, Elizabeth 3rd. Jumin is a quiet, serious, and cautious man who, as the oldest, acts as the logical and pragmatic voice of the group, presenting himself as the most mature.