Japan's government bond yield curve steepened slightly in early Tokyo trade as Friday's steepening in the U.S. Treasury market fed through to JGBs, while softer-than-expected first preliminary second-quarter real GDP data reduced the perceived likelihood of a BOJ rate hike next month. The weaker growth reading was seen limiting gains in shorter-dated yields even as long-dated bonds came under pressure from lingering concerns over Japan's fiscal spending. The two-year JGB yield rose 1.5 basis points to 1.665%, while the 30-year yield climbed 2 basis points to 4.030%.