In 2023, Sano travels with his old friend Miyata to the seaside hotel where five years earlier he met Nagi, the woman he fell in love with and would marry. But recently Nagi passed away, Sano is far from overcoming her death. At the hotel, he not only wants to reminisce, he also hopes to find a new life purpose.
But the hotel, once a popular destination for newlyweds, is not what it used to be; during the pandemic, it lost much of its luster. Sano especially hopes to recover the red baseball cap that Nagi lost there then.