Search gender: all male female Kumagai Boy Name Meaning, Kanji Variations. 1 names found. gender: all male female Name: kumagai Katakana: クマガイ 0 Kanji: 熊谷 Meaning: 熊Bear. Animal names. 谷Valley You can save your favorite names with NAZUKE PON > About Japanese Names > Search For Japanese Names > Kumagai Boy Name Meaning, Kanji Variations.