TOKYO, Jan 15 (Reuters) - Japanese government bonds firmed slightly on Friday, following strong auction results and after U.S. President-elect Joe Biden’s stimulus proposals contained little in the way of surprises. The liquidity-enhancing auction, in which the Ministry of Finance sells an additional amount of existing JGB issued strong bids, traders said. Biden outlined a $1.9 trillion stimulus package proposal, including some $1 trillion in direct relief to households, saying bold investment was needed to jump-start the economy and accelerate the distribution of vaccines. “His comments were in line with what’s been already reported and didn’t become a fresh factor to sell bonds,” said Katsutoshi Inadome, senior strategist at Mitsubishi UFJ Morgan Stanley Securities. The 10-year JGB yield fell 0.5 basis point to 0.025%, while the 20-year JGB yield was flat at 0.410%. At the shorter end, the two-year yield fell 0.5 basis point to minus 0.130% while the five-year yield was flat at minus 0.105%. The 30-year yield bucked the overall trend to rise 0.5 basis point to 0.645%. Benchmark 10-year JGB futures price ended up 0.01 point to 151.85.