Eri Sawachika is one of Tenma's closest friends. She has a wealthy family and has her butler, Nakamura. Judging from her blonde hair, she's not pure Japanese.
In fact, her father is a wealthy European and her mother is half-Japanese. Because of her lineage, she realizes that she Kanji somewhat difficult.
Eri is extremely wealthy. She acts civilized, although sometimes she is rather spoiled and proud. Despite of her social stance, everyone thought that Eri has no reckless side. However, her friends come to realize that she does have one. Eri has a great admiration for her father,
but she can not manage to spend much time with him because he rarely comes home because of work commitments.