Eri has known Nozomi and Noriko since they were young. She first realized how Nozomi felt toward Ryo Hazuki when she was a junior high school student. Moved by Nozomi's pure, deep love for Ryo, she has been supportive to her both openly and secretly. She is angry and often unfriendly with Ryo though, who takes an indecisive attitude toward Nozomi.
Eri seems to be an arrogant, selfish person, but in fact, she is quite insecure and hates being alone. Acting like a big sister, she always feels obligated to protect Nozomi and Noriko who she feels are vulnerable. However she sometimes makes careless mistakes, and Nozomi and Noriko who are more firm and reliable than they look, support her during those times.
- Eri's zodiac sign is Leo and she has a AB blood type,