| Name | Gender | Pronounced | Usage | Popularity |
|---|---|---|---|---|
| Katsurou | kah-tsoo-ṙo: | Japanese | ||
| Kazue | kah-zoo-e | Japanese | ||
| Kazuki | kah-zoo-kee | Japanese | ||
| Kazuko | kah-zoo-ko | Japanese | ||
| Kazuo | kah-zoo-o | Japanese | ||
| Keiko | ke:-ko | Japanese | ||
| Ken (2) | ken | Japanese | ||
| Ken'ichi | ken-ee-chee | Japanese | ||
| Kenji | ken-jee | Japanese | ||
| Kenshin | ken-sheen | Japanese | ||
| Kenta | ken-tah | Japanese | ||
| Kichiro | kee-chee-ṙo: | Japanese | ||
| Kichirou | kee-chee-ṙo: | Japanese | ||
| Kiku | kee-koo | Japanese | ||
| Kimiko | kee-mee-ko | Japanese |