Mumbai, Jan. 20 -- The Japanese yen edged lower to near 158.4 per dollar on Tuesday, following a bout of sharp volatility, as domestic political developments unsettled investor sentiment. Prime Minister Sanae Takaichi's announcement to dissolve parliament and call a snap election on February 8 injected fresh uncertainty, with the scale of the ruling party's majority seen as pivotal for the future direction of fiscal policy. Market participants also remained cautious ahead of the Bank of Japan's two-day policy meeting concluding Friday, preferring to wait for clearer guidance on the timing of the next rate increase. Even so, expectations of an eventual policy shift by the BoJ, the likelihood of official intervention to curb excessive curre...