に就て[nitsuite] concerning
に就き[nitsuki] because of
去就[kyoshuu] committing one's self
就いては[tsuiteha] in line with this
就きましては[tsukimashiteha] in line with this

就く[tsuku] to ascend (the throne)
就ける[tsukeru] to install (a king, emperor, etc.)
就学[shuugaku] entering school
就学義務[shuugakugimu] compulsory school attendance
就学児童[shuugakujidou] school child

悔い[kui] regret
悔いる[kuiru] to regret
悔改める[kuiaratameru] to repent
悔しさ[kuyashisa] chagrin
悔泣[kuyashinaki] crying from vexation

悔み状[kuyamijou] letter of condolence
悔む[kuyamu] to mourn
悔悟[kaigo] remorse
悔恨[kaikon] regret
後悔[koukai] regret