待我长发及腰怎奈君未归
[dài wŏ zhăng fā jí yāo zĕn nài jūn wèi guī]
It's based on an ancient Chinese love poem describing a woman waiting anxiously for her lover to come home, but when she grows her hair long for him, he doesn't return. The phrase expresses deep yearning and sadness. The creator might be reminiscing about a similar experience or expressing admiration for classic Chinese poetry and storytelling.