Quick answer
Yumiko is a girl name.
Meaning and history
From Japanese 弓 ( yumi ) meaning "archery bow" or 由 ( yu ) meaning "reason, cause" with 美 ( mi ) meaning "beautiful" combined with 子 ( ko ) meaning "child". Other kanji combinations are possible.
Notes and context
Usage: japanese | Japanese Hiragana: ゆみこ; Japanese Katakana: ユミコ