呆若久时自然萌傻若久时天然呆
[dāi ruò jiŭ shí zì rán méng shă ruò jiŭ shí tiān rán dāi]
Natural Cuteness Arises From Being Absent-minded for Long; Naturally Dopey When Being Silly for Long. Describes a person's unique charm that stems from long-term natural innocence or silly actions over time leading to genuine adorableness.