Ranmaru is a casual and easy-going boy. He is generally placid in nature, although occasionally flustered, such as when Sara holds his hand. He seems to come off as nervous or awkward in certain situations. Ranmaru also tries to keep quiet and distant until provoked. He thinks ahead before dealing with dangerous scenarios, showing his level-headedness and his good perception. He is shown to be compassionate and expresses a want to be useful to others. He's shown to be cooperative.