TOKYO, April 7 (Reuters) - The Bank of Japan (BOJ) is expected to buy 1.2 trillion yen ($12.28 billion) in Japanese government bonds next week with over five years remaining to maturity as it begins a new monetary-easing scheme, the Nikkei business daily said on Sunday. The central bank aims to make five purchases totalling 6.2 trillion yen in April. After that, it plans to make monthly purchases of about 7.5 trillion yen in six instalments, the Nikkei said in an unsourced report. A bank spokesman said no one was immediately available to comment on the Nikkei report. The bank said on Thursday it would radically overhaul its monetary policy and inject about $1.4 trillion into the economy in less than two years by buying government bonds across the yield curve. It also said it would combine two bond-buying programmes, its asset-buying and lending plan and the "rinban" bond-buying market operation, to buy JGBs with all maturities. Monthly JGB purchases under the new programme will total about 70 percent of newly issued debt. Yields on benchmark 10-year Japanese government bonds sank to a record low of 0.315 percent on Friday. Last week's meeting was the first chaired by Governor Haruhiko Kuroda since he took the helm of the central bank last month with a vow to take aggressive steps to defeat deflation.