Leo is spending the night at Caillou’s. Mom, Dad and Caillou provide him with all he needs: a sleeping bag to sleep in and a new toothbrush. Caillou would like all these special treats too but he learns that the guest comes first. Although Caillou gets a bit frustrated by this, he has a change of heart when he sees that Leo misses home a bit. Caillou decides to lend Leo his favorite dinosaur pajamas. The two friends find a perfect solution to make them both happy and have the best sleep-over ever!