We search for electron anti-neutrinos (νe) from long and
short-duration gamma-ray bursts~(GRBs) using data taken by the KamLAND detector
from August 2002 to June 2013. No statistically significant excess over the
background level is found. We place the tightest upper limits on
νe fluence from GRBs below 7 MeV and place first constraints on
the relation between νe luminosity and effective temperature.Comment: 16 pages and 5 figure