Search gender: all male female ユイイチ Japanese Boy Names Variations. 1 names found. gender: all male female Name: yuichi Katakana: ユイイチ 0 Kanji: 唯一 Meaning: 唯That's it. Just one. Only. A word expressing limitation or emphasis. Reply. A reply of acceptance that is answered immediately. 一One. The first. Kanji for the number 1 (one). To be the most superior. To begin, to put things together. You can save your favorite names with NAZUKE PON > About Japanese Names > Search Japanese Names By Kanji > ユイイチ Japanese Boy Names Variations.