The remarriage of Shizuka's father gave him a new younger brother. This new brother Motoya has a foreign grandparent so he's tall, a little bit quiet, but very gentle. Motoya was pleased that his family has increased, but his "brother" Shizuka somehow seemed depressed.
Truth is, Shizuka was in love with Motoya at firs sight. In order to become a "good family" like everybody's wish, Shizuka began to avoid Motoya to suppress his intense feelings, but one day he was cornered by inquisitive Motoya and couldn't escape...?!