内容简介：

       李上晴拥有一个不能说的秘密——她住在“山芭”里。她不想让同学知道，因为她害怕被同学嘲笑。连她最要好的朋友张咪芬，也不曾去过她家。

        
虽然她住的地方没有水、没有电，甚至连抽水马桶也没有，但那里却有着美丽的自然景观。每天，她都跟哥哥李上游去牧羊。

有一天，他们不顾爸爸的叮咛，偷偷到西北山去牧羊。结果他们果真在山上迷了路，幸好最终遇上好心的宋叔叔，载他们回家。

李上晴做梦也没想到，宋叔叔就是她的班长宋亦翔的大伯。她的秘密因而公开，张咪芬更因误会要跟她绝交。李上晴虽难过，但却不得不打起精神，为即将来临的演讲比赛作准备。

眼看比赛的日子越来越近，李上晴却竟然一连缺课了四天。与此同时，宋亦翔的大伯也失踪了四天没有回家。到底他们发生了什么事？李上晴会不会出席演讲比赛？她跟张咪芬的误会能解开吗？

《星空下的约定》，让你亲身体验一场前所未有的自然之旅，随着书中各人一起经历喜怒哀乐，一同成长。

This story revolves around a young girl by the name of Li Shand Qing. She is very secretive about her residence and she doesn’t want her classmates to know and laugh at her that she’s staying in a very remote area without an electricity, water and modern sanitation. However the surroundings are very beautiful and natural.

Whenever, her brother and she are free, they will help their father to look after the goats and one day, when they didn’t listen to their father’s advice against herding the goats to the north - west area to graze the grass, they lost their way home!

Luckily, they met an elderly man by the name of Uncle Soong who was so kind hearted to send them home. Coincidentally, the elderly man was her class monitor’s uncle and soon her secret was known to everyone. Her best friend ended their friendship. She was very sad and to make things worse, she had to get herself prepared for the coming speech / oratory competition!