Suzu is generally a relaxed, calm and easy going girl. She has an odd love for hot baths and she speaks like an old man (for example: using "washi" to refer to herself instead of "watashi").
It was revealed in episode 7 that she suffers from a rare disease called the Highlander Syndrome, which hinders her ability to age. Her wish was for this illness to be cured and to be able to die normally. She tries to kill Haru by installing a bomb onto her breather, and the only way to get it off is by typing in a 4-digit combo. In the end, Tokaku and Haru manage to obtain the code (which was the birth date of Suzu's loved one), and Suzu is soon expelled.