N5
ええ、えー
Definition
yes, that is correct, right, um, errr, huh?, grrr, gah, Must I?, good
N4
こう
Definition
school, proof (of a book, document, etc.), counter for proofs
N3
しよう
Definition
use, application, employment, utilization, utilisation
N2
しようがない、しょうがない
Definition
it can't be helped, it is inevitable, nothing can be done, there's no point (in doing something), there's no reason (to do something)
N1
きゅうくつ
Definition
narrow, tight, cramped, formal, stiff, strict, ceremonious, rigid, constrained, uncomfortable, tight (e.g. finances)