last season
Refers to the previous season in sports, fashion, TV, or other recurring cycles.
昨シーズン、彼はリーグMVPを獲得した。
Last season, he won the league MVP.
昨シーズンのトレンドはもう古い。
Last season's trends are already outdated.
Compound of 昨 (saku, 'last') and シーズン (shiizun, 'season').