Nakanmon!

From Day of the River:

Our crybaby protagonist Hirahara Tsukasa hasn't always been a crybaby. Due to the death of her older sister Chihiro, Tsukasa hasn't been able to dam up the flood of tears ever since - even about little things.

She is further disheartened after moving to Tokyo from Hiroshima, especially after a series of incidents cause her and her four classmates to miss the bus and be late for the entrance ceremony on the very first day of the school term. However, it is precisely this event that ends up drawing her closer to maturity and fueling her determination to stop her crybaby tendencies. And perhaps, she may even find an unexpected love on the way...