After the death of Hidenage TOYOTOMI, Ichian served with Masatsugu KOBORI as chief retainers to Hidenaga's adopted son Hideyasu TOYOTOMI and, when Hideyasu died suddenly in May 1594 the TOYOTOMI family's grip on the Dainagon (chief councilor of state) role was severed.
秀長の没後は、養子豊臣秀保に小堀正次とともに家老として仕えたが、文禄3年（1594年）4月、秀保がにわかに没して豊臣大納言家は断絶した。