  Exo-NINJA will realize nearIR R$\sim$4000 diffraction-limited narrow-field
spectro-imaging for characterization of exoplanets and circumstellar disk
structures. It uniquely combines mid-R spectroscopy, high throughput, and
spatial resolution, in contrast to CHARIS, which does spectro-imaging, and
REACH, which is single-point (no spatial resolution). Exo-NINJA's
spectro-imaging at the telescope diffraction limit will characterize exoplanet
atmospheres, detect and map (spatially and spectrally) gas accretion on
protoplanets, and also detect exoplanets at small angular separation
($\lambda$/D) from their host star by spectro-astrometry. Exo-NINJA will link
two instruments at the Subaru Telescope using a high-throughput hexagonal
multi-mode fiber bundle (hexabundle). The fiber coupling resides between the
high contrast imaging system SCExAO, which combines ExAO and coronagraph, and
the medium-resolution spectrograph NINJA (R$=$4000 at JHK bands). Exo-NINJA
will provide an end-to-end throughput of 20% compared to the 1.5% obtained with
REACH. Exo-NINJA is scheduled for implementation on the Subaru Telescope's
NasIR platform in 2025; we will present a concise overview of its future
installation, laboratory tests such as the throughput and focal ratio
degradation (FRD) performance of optical fiber imaging hexabundles, in the NIR
and the trade-offs for fiber choices for the NINJA-SCExAO hexabundle fiber
cable, and the expected on sky performance.
