Natsumi is a young woman with long red hair that has dark roots tied up at the back of her head with bangs hanging on the right side.
She wears a gray tracksuit when working in her family's workshop. Sorawo's first impression of her is that she looked like a delinquent.
(To be added soon.)
After graduating from high school, Natsumi chose not to continue her studies and instead work at her family's car mechanic factory. Sorawo Kamikoshi and Toriko Nishina, who were informed by Akari Seto, helped Natsumi's family who was involved in the entity known as Sannukikano. She used to be wary of Satsuki and skeptical of Sorawo. After Sorawo and Toriko helped her, as a thank-you, she undertook the modification of AP-1.
- The name Natsumi means "summer" (夏) (natsu) and "queen, princess" (妃) (mi).
- Natsumi's surname Ichikawa means "city, market, town" (市) (ichi) and "river, stream" (川) (kawa).
- Natsumi's family runs a workshop that she'd been helping out ever since high school.