Moms Juniorcare for Old Virgin Lady

Golden Week has begun... A friend comes to Shizuka's house with her son, whom they haven't seen for a long time. She says she is going on vacation with friends, and leaves her son with Shizuka. The son's name is Seva.
Unlike his mom, he is a good boy. Shizuka has a burning deadline on her order, so it's not her, but Seva who takes care of her.
Will Shizuka be able to turn in the order on time? What will happen during this week? And will Seva find out about her secret...?