Natsumi Hikari (光 夏海 Hikari Natsumi, referred to as "Natsumikan" by Tsukasa and "Natsumelon" by Daiki) is a young woman who works at the Hikari Photo Studio under her grandfather, Eijiro Hikari, having lived with him since childhood. Eventually, she becomes Kamen Rider Kiva-la (仮面ライダーキバーラ Kamen Raidā Kibāra, Masked Rider Kiva-la), a Kamen Rider appearing in Kamen Rider Decade: The Last Story. Similar to other riders in the series, Kiva-la is an original Kamen Rider with origins coming from an A.R. World. Though unlike them, Natsumi does not come from an A.R. World, she only used her powers once.