also: センティメンタル
Describes a person, feeling, story, or atmosphere that is overly emotional, nostalgic, or tender in a somewhat self-indulgent way. Often carries a slightly negative nuance of being excessively emotional.
He was feeling sentimental and looking at old photos.
その映画はセンチメンタルすぎて、少しわざとらしく感じた。
That movie was too sentimental and felt a bit contrived.
Looking at old photos, I got into a sentimental mood.
As graduation approaches, I feel sentimental.
He always gets sentimental when he talks about the old days.