Financial assets held by households rose 4.4 percent from a year earlier to a record ¥1.832 quadrillion ($16 trillion) at the end of June, up for the fourth straight quarter, Bank of Japan data showed Wednesday.
The growth was boosted by the increasing value of stocks and other assets amid a moderate global economic expansion. By asset type, equities rose 22.5 percent to ¥191 trillion and investment trusts increased 15.6 percent to ¥100 trillion.
Cash and deposits, which accounted for 51.6 percent of household assets, rose 2.6 percent to a record ¥945 trillion.
The data also showed that the BOJ's holdings of Japanese government bonds rose above 40 percent of the total for the first time, climbing 9.9 percent from a year earlier to ¥437 trillion.
The central bank buys vast amounts of the debt as part of its aggressive monetary easing measures aimed at lifting the economy and spurring inflation toward 2 percent.
Meanwhile, the outstanding balance of government bonds fell 2.1 percent to ¥1.085 quadrillion, down for the first time in roughly eight years as debt yields rose from their lows a year earlier. Yields move inversely to debt prices.
Government bonds held by foreign investors gained 4.9 percent to ¥117 trillion, comprising 10.8 percent of the total.