From here:
The basic story: a high-school student (Nanase Hokuto) living away from his parents (who are in Australia) shares an apartment house with three older girls. His exposure to their whimsical and teasing nature leaves him pretty much despising females. However, the high-school idol (Taniyama Maina) ends up having a crush on him. Her best friend is Nakajima Atsumi, your…