Japan's S&P Global Manufacturing PMI eased to 54.5 in May from April's 51-month high of 55.1, with input costs and selling prices rising at rates rarely seen in over 24 years of data. Summary:Source: S&P GlobalThe headline Japan Manufacturing PMI fell to 54.5 in May from April's 51-month high of 55.1, marking a fifth consecutive month of improvement in sector healthOutput and new orders both rose at historically strong rates, though the pace of expansion eased from April; new export orders grew at the fastest pace in five yearsStock building by manufacturers and clients, driven by Middle East war disruption and rising costs, was cited as a significant driver of the apparent demand strengthInput costs rose to their highest since September 2022 and selling prices increased at the fastest pace since October 2022, with metals, oil-based products, labour and transportation all citedSupplier delivery times lengthened at one of the fastest rates outside the pandemic period, linked directly to Middle East war supply chain disruptionEmployment grew at the second-quickest pace in over four years; business confidence edged up from April's one-year low but remained below its historical averageJapan's manufacturing sector extended its expansion into a fifth consecutive month in May, with output and new orders rising at historically strong rates, though the headline PMI eased from April's 51-month peak and a deepening inflation surge pointed to growing cost pressures across the sector.S&P Global Japan Manufacturing PMI, May 2026: 54.5prior: 55.1 (51-month high)The survey's details carry an important qualifier. A significant portion of the apparent demand strength reflects precautionary stock building by manufacturers and their clients, with firms accumulating inventories to guard against product shortages and further price increases driven by the Middle East war. Semiconductors and oil-based products were specifically cited. New export orders, rising at their fastest pace in five years, provided a more genuine demand signal, though supply chain constraints meant delivery times lengthened at one of the fastest rates recorded outside the pandemic.Cost pressures were the survey's starkest finding. Input costs rose to their highest since September 2022 and selling prices accelerated to their fastest since October 2022, with raw materials, energy, labour and transportation all contributing. Analysts at S&P Global warned that surging costs and subdued global conditions could act as headwinds in the months ahead, even as firms retain cautious optimism around AI and electronics demand.--A reading of 54.5 remains firmly expansionary and will support the BOJ's case that the domestic manufacturing economy is robust enough to absorb a June rate hike, which markets have increasingly priced in. The inflation detail, however, is the more consequential signal: input costs at their highest since September 2022 and selling prices at their fastest since October 2022 add to the imported inflation picture that complicates the BOJ's gradualist messaging. The stock-building dynamic, with manufacturers and clients alike accumulating safety inventories against further Middle East disruption, means the current demand signal overstates genuine end-user consumption and could unwind sharply if the Hormuz situation resolves. Export orders growing at the fastest pace in five years is yen-sensitive, reinforcing the case for a stronger currency at a time when the MOF is watching intervention thresholds closely. This article was written by Eamonn Sheridan at investinglive.com.