要因 | youin - Translation and Meaning in Japanese The Japanese word 「要因」 (youin) is composed of two kanji: 「要」 and 「因」 The kanji 「要」 (you) means "essential" or "necessary," while 「因」 (in) carries the meaning of "cause" or "factor " Together, these kanji form a term that is translated as "factor" or "main cause "