On her birthday, her boyfriend Reiji Todoriki bought matching rings that she wanted and was going to pick her up by motorcycle, but he hit his head on a street phone pole and fell in a coma.
She learns from Rinne and Sakura that his spirit had left his body for a reason, and a demon Masato tricked him into believing that she started dating his best friend Tomoya Tadano, as part of what she considers a stupid revenge against Rinne. After many torments including rolling over Tomoya, Suzu begun to feel disgusted of him. But after Sakura and Rokumon found and brought his gift for her back to the hospital, Suzu bursts into tears next to Reiji's body. Nevertheless, Reiji's spirit returned to his body thanks to Rinne, he awoke and she forgave him.
- Her last name means Three waves.
- Her romance with Reiji is more explored in the anime.