Emi looks forward to her weekend visits to her dad's, but she's sad that her Shiba Inu puppy, Rina, can't come too. During the school holidays, Emi visits her dad for four whole days, and Rina is restless - what if Emi doesn't come back? Determined to find her owner, Rina escapes and heads to the last place she saw Emi - the railway station...