  We have conducted a NanoSIMS-based search for presolar material in samples
recently returned from C-type asteroid Ryugu as part of JAXA's Hayabusa2
mission. We report the detection of all major presolar grain types with O- and
C-anomalous isotopic compositions typically identified in carbonaceous
chondrite meteorites: 1 silicate, 1 oxide, 1 O-anomalous supernova grain of
ambiguous phase, 38 SiC, and 16 carbonaceous grains. At least two of the
carbonaceous grains are presolar graphites, whereas several grains with
moderate C isotopic anomalies are probably organics. The presolar silicate was
located in a clast with a less altered lithology than the typical extensively
aqueously altered Ryugu matrix. The matrix-normalized presolar grain abundances
in Ryugu are 4.8$^{+4.7}_{-2.6}$ ppm for O-anomalous grains, 25$^{+6}_{-5}$ ppm
for SiC grains and 11$^{+5}_{-3}$ ppm for carbonaceous grains. Ryugu is
isotopically and petrologically similar to carbonaceous Ivuna-type (CI)
chondrites. To compare the in situ presolar grain abundances of Ryugu with CI
chondrites, we also mapped Ivuna and Orgueil samples and found a total of SiC
grains and 6 carbonaceous grains. No O-anomalous grains were detected. The
matrix-normalized presolar grain abundances in the CI chondrites are similar to
those in Ryugu: 23 $^{+7}_{-6}$ ppm SiC and 9.0$^{+5.3}_{-4.6}$ ppm
carbonaceous grains. Thus, our results provide further evidence in support of
the Ryugu-CI connection. They also reveal intriguing hints of small-scale
heterogeneities in the Ryugu samples, such as locally distinct degrees of
alteration that allowed the preservation of delicate presolar material.
