Junpaku no Wedding Dress de Fukushuu wo

Saki was looking forward to her wedding with her fiancé, Riku. However, when Saki returns from a business trip and opens her closet to put away the suit she took off, the dress she had saved is gone! It was a very important dress.... Saki had a bad premonition and contacted Riku, who informed her that he had loaned it to Aijitsu, who is getting married today...? Why is my husband's childhood friend supposed to wear my precious wedding dress?