Yen loans if available in your country is beneficial since like you say the interest rates are advantageous. Moreover yen is always kept weak so you might wind up paying less when you convert your dollar payment to yen. It fluctuate between 118 and 120 and sometimes even more. Always yen when you have an option. Historically Japanese keep their yen undervalued to support their export industries even though the yen has upward pressure. They do one thing or the other tampering with their economy to make yen lower. This will continue since there was no upward movement for long. Is it possible to get yen loan in US?