Quick answer
Natsumi is a girl name.
Meaning and history
From Japanese 夏 ( natsu ) meaning "summer" and 美 ( mi ) meaning "beautiful". It can also come from 菜 ( na ) meaning "vegetables, greens" and 摘 ( tsumi ) meaning "pick, pluck". Other kanji combinations are possible.
Notes and context
Usage: japanese | Japanese Hiragana: なつみ; Japanese Katakana: ナツミ