Search gender: all male female 琉夏 Japanese Boy Names Variations. 1 names found. gender: all male female Name: ruka Katakana: ルカ 3 Kanji: 琉夏 Meaning: 琉Ruri(lapis lazuli). Name of a gemstone. A deep blue to indigo-colored gemstone. One of the seven treasures. 夏Summer. It is one of the four seasons. Big. Prosperous. The name of a dynasty or country in China. China's own name. You can save your favorite names with NAZUKE PON > About Japanese Names > Search Japanese Names By Kanji > 琉夏 Japanese Boy Names Variations.