Japan's government bonds dropped on Friday falling four fourth day this week as demand for securities was curbed by the Bank of Japan's offer to purchase short- to long-term securities in a total value of 2.51 trillion yen ($25.3 billion). The Japanese benchmark 10-year yield increased by six basis points to 0.635% at 4:24 p.m. Tokyo time after the rate touched its lowest at 0.315 on April 5.