Most of the time, Shinji maintains a somewhat frivolous and carefree air, seemingly indifferent to everything happening around him. However, he is actually a very perceptive person, sensitive to the behavior of those close to him, and one of the few who glimpsed Aizen's true nature from the beginning. His nonchalant and apathetic attitude always irritates Hiyori Sarugaki, leading to frequent arguments between them. This gives Hirako a certain comical air due to the immaturity he displays in these moments, provoking his partner. Nevertheless, when it comes to fighting, he abandons his nonchalance and lack of interest, acquiring a great seriousness that he also displays when he is annoyed.