N5
たのしい
Definition
enjoyable, fun
N4
ふくしゅう
Definition
review, revision
N3
たま
Definition
ball, sphere, globe, orb, bead (of sweat, dew, etc.), drop, droplet, ball (in sports), pile (of noodles, etc.), bullet, bulb (i.e. a light bulb), lens (of glasses, etc.), bead (of an abacus), ball (i.e. a testicle), gem, jewel (esp. spherical; someti...
N2
ためる
Definition
to amass, to accumulate, to store, to leave unpaid
N1
こうじょう
Definition
elevation, rise, improvement, advancement, progress