Aika S. Granzchesta, the distinguished successor and branch manager of Himeya Company, an association which offers shelter to female gondoliers known as Undines, surprises everyone by rejecting tradition and refusing to inherit the company's renowned gondola. Her apprentice, Azusa B. McLaren, fails to comprehend her mentor's unexpected decision and confronts her, only to find little impact. Azusa and her fellow Undines scheme to organize a gathering with Aika secretly to better understand her rationale. The anticipation of winter, paired with the tranquillity and beauty of Neo-Venezia, causes Aika to reflect on her journey as an Undine, bringing her to the person she is now. As she reminisces on the past's valuable experiences, Aika trusts them to lead her fearlessly into the limitless, unknown future.