expression, noun
sentimental novel; sappy story
Refers to a novel or story that is overly sweet, romantic, or emotionally indulgent, often with a slightly negative or dismissive tone.
彼女は甘い小説ばかり読んでいる。
She only reads sentimental novels.
Compound of 甘い (sweet, naive) and 小説 (novel). The exact origin is uncertain, but it likely arose as a descriptive phrase for overly sentimental fiction.