Shiina Kanna is the healthy main character girl that gets perved on in manga series Ookii Muki Muki Chiisai Muchi Muchi. Just don't tell her she's deliciously chubby, because as she insists, she's definitely not.

The main trigger is Shiina Kanna.

For a description, I'd go with 1girl, green eyes, black hair, short hair, bangs, thick eyebrows, bob cut, blunt bangs, plump, breasts, large breasts.