The works of the Sendai group on investigations of the properties of t
he trinucleon bound states H-3 and He-3 are reviewed in detail. For th
ese mirror nuclei, results are summarized that have been obtained from
rigorous solutions of the (Coulomb-modified) Faddeev equations for va
rious realistic nucleon-nucleon potentials with inclusion of three-nuc
leon forces as well as charge-independence- and charge-symmetry-breaki
ng forces. It becomes evident that for most trinucleon bound-state obs
ervables quite reasonable results have been achieved.